Adventure game

An adventure game is a video game in which the player assumes the role of protagonist in an interactive story driven by exploration and puzzle-solving. The genre's focus on story allows it to draw heavily from other narrative-based media such as literature and film, encompassing a wide variety of literary genres. Nearly all adventure games (text and graphic) are designed for a single player, since this emphasis on story and character makes multi-player design difficult.

In the Western world, the genre's popularity peaked during the late 1980s to mid-1990s when many considered it to be among the most technically advanced genres, but it is now sometimes considered to be a niche genre. In East Asia on the other hand, adventure games continue to be popular in the form of visual novels, which make up nearly 70% of PC games released in Japan.

Definition
The term "Adventure game" originates from the 1970s text computer game Adventure, which pioneered a style of gameplay that was widely imitated and became a genre in its own right. The video game genre is therefore defined by its gameplay, unlike the literary genre, which is defined by the subject it addresses, the activity of adventure.

Essential elements of the genre include storytelling, exploration, and puzzle solving. Adventure games have been described as puzzles embedded in a narrative framework, where games involve "narrative content that a player unlocks piece by piece over time". While the puzzles that players encounter through the story can be arbitrary, those that do not pull the player out of the narrative are considered examples of good design.

Relationship to other genres
Combat and action challenges are limited or absent in adventure games, thus distinguishing them from action games. In the book Andrew Rollings and Ernest Adams on Game Design, the authors state that "this [reduced emphasis on combat] doesn't mean that there is no conflict in adventure games ... only that combat is not the primary activity." Some adventure games will include a minigame from another video game genre, which are not always appreciated by adventure game purists. Of course, there are some games that blend action and adventure throughout the game experience. These hybrid action-adventure games involve more physical challenges than pure adventure games, as well as a faster pace. This definition is hard to apply, however, with some debate among designers about which games are action games and which involve enough non-physical challenges to be considered action-adventures.

Adventure games are also distinct from role-playing video games that involve action, team-building, and points management. Adventure games lack the numeric rules or relationships seen in role-playing games, and seldom have an internal economy. These games lack any skill system, combat, or "an opponent to be defeated through strategy and tactics." However, some hybrid games exist here, where role-playing games with strong narrative and puzzle elements are considered RPG-adventures. Finally, adventure games are classified separately from puzzle games. Although an adventure game may involve puzzle-solving, they typically involve a player-controlled avatar in an interactive story.

Puzzle-solving
Adventure games contain a variety of puzzles, such as decoding messages, finding and using items, opening locked doors, or finding and exploring new locations. Solving a puzzle will unlock access to new areas in the game world, and reveal more of the game story. Logic puzzles, where mechanical devices are designed with abstract interfaces to test a player's deductive reasoning skills, are common.

Some puzzles are criticized for the obscurity of their solutions, for example the combination of clothesline, clamp, and deflated rubber duck used to gather an item in The Longest Journey, which exists outside of the game's narrative and serves only as an obstacle to the player. Others have been criticized for requiring players to blindly guess, either by clicking on the right pixel, or by guessing the right verb in games that use a text interface. Games that require players to navigate mazes have also become less popular, although the earliest text-adventure games usually required players to draw a map if they wanted to navigate the abstract space.

Gathering and using items
Many adventure games make use of an inventory management screen as a distinct gameplay mode. Players are only able to pick up some objects in the game, so the player usually knows that only objects that can be picked up are important. Because it can be difficult for a player to know if they missed an important item, they will often scour every scene for items. For games that utilize a point-and-click device, players will sometimes engage in a systematic search known as a pixel hunt. Games try to avoid this by highlighting the item, or by snapping the player's cursor to the item.

Many puzzles in these games involve gathering and using items from their inventory. Players must apply lateral thinking techniques where they apply real-world extrinsic knowledge about objects in unexpected ways. For example, by putting a deflated inner tube on a cactus to create a slingshot, which requires a player to realize that an inner tube is stretchy. They may need to carry items in their inventory for a long duration before they prove useful, and thus it is normal for adventure games to test a player's memory where a challenge can only be overcome by recalling a piece of information from earlier in the game. There is seldom any time pressure for these puzzles, focusing more on the player's ability to reason than on quick-thinking.

Story, setting, and themes
Adventure games are single-player experiences that are largely story-driven. More than any other genre, adventure games depend upon their story and setting to create a compelling single-player experience. They are typically set in an immersive environment, often a fantasy world, and try to vary the setting from chapter to chapter to add novelty and interest to the experience. Comedy is a common theme, and games often script comedic responses when players attempt actions or combinations that are "ridiculous or impossible".

Since adventure games are driven by storytelling, character development usually follows literary conventions of personal and emotional growth, rather than new powers or abilities that affect gameplay. The player often embarks upon a quest, or is required to unravel a mystery or situation about which little is known. These types of mysterious stories allow designers to get around what Ernest W. Adams calls the "Problem of Amnesia", where the player controls the protagonist but must start the game without their knowledge and experience. Story-events typically unfold as the player completes new challenges or puzzles, but in order to make such storytelling less mechanical new elements in the story may also be triggered by player movement.

Dialogue and conversation trees
Adventure games have strong storylines with significant dialog, and sometimes make effective use of recorded dialog or narration from voice actors. This genre of game is known for representing dialog as a conversation tree. Players are able to engage a non-player character by choosing a line of pre-written dialog from a menu, which triggers a response from the game character. These conversations are often designed as a tree structure, with players deciding between each branch of dialog to pursue. However, there are always a finite number of branches to pursue, and some adventure games devolve into selecting each option one-by-one. Conversing with characters can reveal clues about how to solve puzzles, including hints about what that character would want before they will cooperate with the player. Other conversations will have far-reaching consequences, such as deciding to disclose a valuable secret that has been entrusted to the player. Characters may also be convinced to reveal their own secrets, either through conversation or by giving them something that will benefit them.

Goals, success and failure
The primary goal in adventure games is the completion of the assigned quest. Early adventure games often had high scores and some, such as Zork, also assigned the player a rank, a text description based on their score. High scores provide the player with a secondary goal, and serve as an indicator of progression. While high scores are now less common, external reward systems such as Xbox Live's Achievements perform a similar role.

The primary failure condition in adventure games, inherited from more action-oriented games, is player death. Without the clearly identified enemies of other genres, its inclusion in adventure games is controversial, and many developers now either avoid it or take extra steps to foreshadow death. Some early adventure games trapped the players in unwinnable situations without ending the game. Infocom's text adventure The Hitchhiker's Guide to the Galaxy has been criticized for a scenario where failing to pick up a pile of junk mail at the beginning of the game prevented the player, much later, from completing the game.

Text adventure
Text adventures, also known as Interactive Fiction, convey the game's story through passages of text, revealed to the player in response to typed instructions. Early text adventures, such as Adventure, "Hugo's House of Horrors" and Scott Adams' games, used a simple verb-noun parser to interpret these instructions, allowing the player to interact with objects at a basic level, for example by typing "get key" or "open door". Later text adventures, and modern interactive fiction, can interpret far more complex sentences like "take the key which is on the desk, then open the door".

Graphic adventure
Graphic adventures are adventure games that use graphics to convey the environment to the player. Games under the graphic adventure banner may have a variety of input types, from text parsers to touch screen interfaces. Point-and-click adventures are a common type of graphic adventure in which the player uses a pointer, typically a mouse, to interact with the environment and solve puzzles. This input method remains popular in the genre, and is well-suited to interaction with the environment, as opposed to direct control schemes which emphasize character control.

Graphic adventure games will vary in how they present the avatar. Some games will utilize a first-person or third-person perspective where the camera follows the player's movements, whereas many adventure games use a context-sensitive camera that is positioned to show off each location to the best effect.

One kind of graphic adventure is the Escape the room sub-genre, consisting of short games where the sole object is to find a way to escape from a room. These games are typically implemented in a graphic point-and-click style, which (owing to their popularity on the Internet) are often delivered in Adobe Flash format. Examples of the sub-genre include the Submachine-series, Mystery of time and space and Crimson room. They may also incorporate puzzles and elements typical of a puzzle adventure, such as the inclusion of logic puzzles, elements which occur less often in more traditional adventure games.

Puzzle adventure
Puzzle adventures are adventure games that put a strong emphasis on logic puzzles, at the expense of more traditional inventory puzzles. Instead, they typically emphasize self-contained puzzle challenges that can resemble children's logic puzzle toys or games.

The plot of these games can be obscure, and may be conveyed only through interaction with the puzzles. Many puzzle adventures are played from a first person perspective with the player "moving" between still pre-rendered 3D images, sometimes combined with short animations or video. Examples of the genre include Schizm, Atlantis: The Lost Tales, Riddle of the Sphinx, Zack & Wiki: Quest for Barbaros' Treasure, and Myst, which popularized this game style.

Other puzzle adventure games are casual adventure games made up series of puzzles used to explore and progress the story, such as Puzzle Agent, or Castle of Dr. Brain, and the Professor Layton series.

Visual novel


A visual novel (ビジュアルノベル) is an adventure game featuring mostly static graphics, usually with anime-style art. As the name might suggest, they resemble mixed-media novels or tableau vivant stage plays. Visual novels are especially prevalent in Japan, where they make up nearly 70% of PC games released. They are rarely produced for video game consoles, but the more popular games are sometimes ported to systems such as the Dreamcast or the PlayStation 2. The market for visual novels outside of East Asia, however, is limited.

Visual novels overlap with Japanese adventure games in many ways, including a menu-based interface for all navigation and interaction, reminiscent of ICOM games. Japanese adventure games are driven by narrative, focusing almost exclusively on character interaction, in a structure similar to a Choose Your Own Adventure story. Visual novels frequently feature romantic storylines in which the main character may end up with one of several possible mates.

Visual novels have been a staple of PC software sales in Japan and other East Asian countries for over a decade, so much so that popular titles are open ported to consoles, and some even have famous manga and anime series based upon them; such titles include Kanon (1999), Air (2000) and Clannad (2004) by Key; Rumbling Hearts (2001) by âge; School Days (2005) by 0verflow; Higurashi no Naku Koro ni (2002) by 07th Expansion; and Fate/stay night (2004) by Type-Moon.

A popular subgenre of visual novels is the "crying game" (nakige). The main purpose of such a game is to make the player feel for the characters and make them cry due to emotional scenarios which serves to leave a bigger impact on the player after the game is over. These games often follow a similar formula: a comedic first half with a heart-warming romantic middle followed by a tragic separation and finally (though not always) an emotional reunion. This subgenre originated from the companies Leaf, Tactics and Key. One of the most acclaimed visual novels of this subgenre was Key's Clannad, released in 2005, with a story revolving around the central theme of the value of having a family. It was voted the best bishōjo game of all time in a poll held by Dengeki G's Magazine.

Non-linear branching storylines are a common trend in visual novels, which frequently use multiple branching storylines to achieve multiple different endings, allowing non-linear freedom of choice along the way. Decision points within a visual novel often present players with the option of altering the course of events during the game, leading to many different possible outcomes. A recent acclaimed example is 999: Nine Hours, Nine Persons, Nine Doors, where nearly every action and dialogue choice can lead to entirely new branching paths and endings. Each path only reveals certain aspects of the overall storyline and it is only after uncovering all the possible different paths and outcomes through multiple playthroughs that everything comes together to form a coherent well-written story.

Early development
The first adventure games to appear were text adventures (later called interactive fiction), which typically use a verb-noun parser to interact with the user. These evolved from early mainframe titles like Hunt the Wumpus (Gregory Yob) and Adventure (Crowther and Woods) into commercial games which were playable on personal computers, such as Infocom's widely popular Zork series. Some companies that were important in bringing out text adventure games were Adventure International, Infocom, Level 9 Computing, Magnetic Scrolls and Melbourne House, with Infocom being the best known.

Most text adventures tell the story as if the player himself inhabited the game world. The games do not specify any details about the protagonist, allowing the player to imagine him- or herself as the avatar.

Adventure (1975–1977)


In the mid-1970s, programmer, caver, and role-player William Crowther developed a program called Adventure. Crowther, an employee at Bolt, Beranek and Newman (a Boston company involved with ARPANET routers) used the company's PDP-10 to create the game, which required 300 kilobytes of memory.

The game used a text interface to create an interactive adventure through an underground cave system, based on part of the Mammoth Cave system in Kentucky. Crowther's work was later modified and expanded by programmer Don Woods using the SAIL computer at Stanford, and the game became wildly popular among early computer enthusiasts, spreading across the nascent ARPANET in the late 1970s.

The combination of realistic cave descriptions and fantastical elements proved immensely appealing, and defined the adventure game genre for decades to come. Swords, magic words, puzzles involving objects, and vast underground realms would all become staples of the text adventure genre.

The "Armchair adventure" soon spread beyond college campuses as the microcomputing movement gained steam. Numerous variations of Adventure appeared throughout the late 1970s and early 1980s, with some of these later versions being re-christened Colossal Adventure or Colossal Caves.

Adventure International (1978–1985)
One of the many fans of the Colossal Cave was programmer Scott Adams. Upon his first introduction to Adventure, Adams spent almost ten days traversing the game before he achieved Adventurer Grandmaster status, the title bestowed on those who scored a perfect 350 in Crowther and Woods' version.

Once he had completed the game, Adams began to wonder how a game like Adventure could be developed on a home computer like his TRS-80. The main obstacle was that home computers such as the TRS-80 did not actually have sufficient memory to run a large game like Adventure. Adams worked around this limitation by developing a high-level language and an interpreter written in BASIC, an approach that would also allow code to be reused to develop further adventure games.

In 1978, Adams founded Adventure International with his wife Alexis in order to sell his games. His first game, Adventureland, was a version of Adventure for the TRS-80 that would become the first commercially sold adventure game. His second game, Pirate Adventure, was an original game in a similar style to Adventure—its source code, written in BASIC, was published in the December 1980 issue of Byte magazine. It wasn't until his third game, Mission Impossible, that Adams began programming in assembly language to improve the speed of his software.

Adventure International went on to produce a total of twelve adventure games before a downturn in the industry led to the company's bankruptcy in 1985.

In 1982, David Peugh discovered a print out of the original source code for the Adventure game on ARPANET while visiting the Stanford computer lab. At the time, he was working at the computer retailer Computerland in Tacoma, Washington. As an added value to prospective customers David Peugh modified the original program content to work on all of the computers that Computerland company sold. He offered each customer a special back door magical word to jump to different locations in the game. The password was "XYZZY" The Adventure game continued to be a free program passed on till he inserted in to the commercial retail realm, giving it away free to customers who bought computers from him. Adventure was one of the first games ever to be played on many of these systems. In the following months Microsoft Adventure was released at a price of $49.95 in a plastic folder shrink wrapped on 8 or 5$1⁄4$ inch floppies. Interestingly, inside the Microsoft Adventure program code were the magic words XYZZY.

Infocom (1979–1989)
Dave Lebling and Marc Blank were students at MIT's Laboratory for Computer Science when they discovered Crowther and Woods' Adventure. Together with Tim Anderson and Bruce Daniels they began to develop a similar game, Zork, which also started life on a PDP-10 minicomputer and was distributed across the ARPANET. On graduation the students, together with their group leader Albert Vezza, decided to form a company to market Zork for home computers, and on 22 June 1979 Tim Anderson, Joel Berez, Marc Blank, Mike Broos, Scott Cutler, Stu Galley, Dave Lebling, J. C. R. Licklider, Chris Reeve, and Albert Vezza incorporated Infocom.

The developers faced the same difficulties as Scott Adams in porting Zork to microcomputers: The PDP-10 version, which would reach a megabyte in size, was enormous for the time, and the Apple II and the TRS-80, the potential targets, each had only 16 kb of RAM. They solved this problem by breaking up the game into three episodes, and developing ZIL (Zork Implementation Language), which could function on any computer by using Infocom's Z-machine, the first virtual machine used in a commercial product, as an intermediary.

In November 1980 the new Zork I: The Great Underground Empire was made available for the PDP-11; One month later, it was released for the TRS-80, with more than 1,500 copies sold between that date and September 1981. That same year, Bruce Daniels finalized the Apple II version and more than 6,000 additional copies were sold. Zork I would go on to sell 378,987 copies by 1986.

The company continued developing text adventure games even as it opened a department for the development of professional software, a department which would never be profitable. High-quality games, with massive, intelligent plots, unequaled syntax analyzers, and meticulous documentation as integral parts of the game, succeeded in all genres.

The writer Douglas Adams produced two games with Infocom, the first based on his popular Hitchhiker's Guide to the Galaxy series and a lesser known adventure game called Bureaucracy, inspired by the difficulties he encountered in moving houses.

With the power of microcomputers increasing and the demand for graphics (which it refused to include in its games until 1987), Infocom saw sales decline and in 1989, having been swallowed up by Activision in 1986, the Infocom division had shrunk to a mere ten employees, compared to 100 at its peak. Although later titles were marketed under the Infocom brand, the Infocom division was shut down, and games developed after 1989 would have no link with the original team.

The demise of Infocom signalled the end of the commercial age of Interactive Fiction, and text parsers were rarely seen in games after 1989. Despite this, the low barrier to entry has ensured that a vibrant and creative community of IF authors continues to thrive on the Internet, using languages such as Inform, which generates files that can be read by Infocom's own Z-machine.

Graphical development
Graphics were introduced in 1980 by a new company called On-Line Systems, which later changed its name to Sierra On-Line. Early graphic adventures, such as Sierra's Mystery House (1980), employed basic vector graphics, but these soon gave way to bitmap graphics drawn by professional artists. Examples include Koei's Night Life and Danchi Tsuma no Yuwaku (1982), Sherwood Forest (1982), Yuji Horii's Portopia Serial Murder Case (1983), The Return of Heracles (which faithfully portrayed Greek mythology) by Stuart Smith (1983), Dale Johnson's Masquerade (1983), Antonio Antiochia's Transylvania (1982, re-released in 1984), Sierra's King's Quest (1984), and Adventure Construction Set (1985), one of the early hits of Electronic Arts.

A number of games were released on 8-bit home computer formats in the 1980s that advanced on the text adventure style originated with games like Colossal Cave Adventure and, in a similar manner to Sierra, added moveable (often directly controllable) characters to a parser or input-system similar to traditional adventures. Examples of this are Gargoyle Games's Heavy on the Magick (1986) which has a text-input system with an animated display screen, and the later Magic Knight games such as Spellbound (1985) which uses a window-menu system to allow for text-adventure style input.

From 1984, a new kind of graphic adventure emerged, following the launch of the Apple Macintosh with its point-and-click interface. The first adventure game to take advantage of the Mac's point-and-click interface was the innovative but relatively unknown Enchanted Scepters released the same year, followed in 1985 with the ICOM Simulations game Deja Vu that completely banished the text parser for a point-and-click interface. That same year, the NES version of Chunsoft's Portopia Serial Murder Case worked around the NES's lack of keyboard by taking advantage of its D-pad to replace the text parser of the original 1983 PC-6001 version with a cursor interface for the NES version. The following year, Square's Suishō no Dragon on the NES took it a step further with its introduction of visual icons and animated scenes. In 1987, ICOM's well-known second follow-up Shadowgate was released, and LucasArts also entered the field with Maniac Mansion, a point-and-click adventure that gained a strong following. A prime example of LucasArts' work is the Monkey Island series.

The introduction of such high-quality bitmap graphics required more substantial storage capacity with many adventure games requiring several diskettes for installation, which would be the case until the CD-ROM made its appearance.

Sierra (1979–1999)


After playing through Adventure on a Teletype terminal, and unable to find many other examples of the fledgling genre, Roberta Williams conceived her own, a detective story inspired by Agatha Christie's novel And Then There Were None and the non-linear gameplay of the board game Clue. After working on the design for a month, she was able to convince her husband, Ken Williams, to stop work on the FORTRAN compiler he was developing in order to work on the game on his Apple II computer.

Originally known as Hi-Res Adventure, Mystery House was the first graphical adventure game, and featured vector graphics of each environment alongside an unexceptional two-word parser. Mystery House sold well and although Ken believed that the gaming market would be less of a growth market than the professional software market, he and Roberta persevered with games. Thus, in 1980 the Williamses founded On-Line Systems, which would later become Sierra On-Line.

Sierra soon took things further. Until this point adventure games were in the first person; images presented the décor as seen through the eyes of the player. Williams's company would introduce a new feature in the King's Quest series: a game in the third person. Taking advantage of the techniques developed in action games which had progressed in parallel, Ken introduced an animated character who represented the player in the game and whom the player controlled. With the 3D Animated Adventures, a new standard was born, and nearly all the industry latched onto it. The commands were still entered on the keyboard and analyzed by a syntax interpreter, as with text adventure games.

Soon after, Sierra had multiple successful series of adventure games running, including King's Quest, Police Quest, Space Quest, Leisure Suit Larry, and Hero's Quest (Quest for Glory), with each containing numerous games. A few years after these series had started, the classic graphics above the command cursor was fully replaced with "point and click" game-play and VGA graphics. Other notable series include Phantasmagoria and Shivers; Sierra's last and most critically acclaimed series was the Gabriel Knight series, which began in 1993 and ended with Sierra's last adventure game in 1999.

Sierra would develop new games and push the boundaries of adventure gaming until its purchase by Cendant in 1998. Then in 1998, Cendant sold off their entire interactive software branch for $1 billion to Havas Interactive, a subsidiary of Vivendi Universal.

Sierra pursued technologies for their games (such as hand-drawn backgrounds, rotoscoped animation, and in-game video) that were more advanced than most other genres at the time. However, the release of the PlayStation marked the end of the adventure game era; as 3D became the dominant graphics format, the mostly 2D adventure market began to shrink.

Through its almost 20 year involvement with the adventure game business, Sierra employed several notable game designers, including Roberta Williams, Jane Jensen, Al Lowe, Scott Murphy, Jeff Tunnell, and Lori Ann and Corey Cole.

Early Japanese Adventures (1982–1986)
In the early 1980s, adventure games began gaining popularity in Japan. The country's computer market was largely dominated by NEC's 8-bit PC-8801 (1981) and 16-bit PC-9801 (1982) platforms, which could display 8 simultaneous colors and had a resolution of 640×400, higher than Western computers at the time, in order to accommodate Japanese text. This in turn had an impact on game design, as NEC PCs became known for adventure games with detailed color graphics, which would eventually evolve into visual novels. NEC soon had several competitors such as the FM-7 (1982), the AV (1985) version of which could display more than 4000 colors in addition to featuring FM synthesis sound. Its 16-bit successor, the FM Towns (1989), could display 24-bit color (16.8 million colors) and featured a CD-ROM drive.

Japan's first domestic adventure games were ASCII's Omotesando Adventure (表参道アドベンチャー) and Minami Aoyama Adventure (南青山アドベンチャー), released for the PC-9801 in 1982. Another early Japanese adventure that same year was MicroCabin's Mystery House, which was unrelated to (but inspired by) the On-Line Systems game of the same name. MicroCabin released a sequel, Mystery House II, for the MSX that same year. The following year, the Japanese company Starcraft released an enhanced remake of On-Line Systems' Mystery House with more realistic art work and depiction of blood.

Due to a lack of content restrictions, some of Japan's earliest adventure games were also bishoujo games with eroge content. In 1982, Koei released Night Life, the first commercial erotic computer game. It was a graphic adventure, with sexually explicit images. That same year, they released another eroge title, Danchi Tsuma no Yuwaku (Seduction of the Condominium Wife), which was an early adventure game with color graphics, owing to the eight-color palette of the NEC PC-8001 computer, and role-playing video game elements. It became a hit, helping Koei become a major software company. Other now-famous companies such as Enix, Square and Nihon Falcom also produced similar eroge in the early 1980s before they became famous for their mainstream role-playing games. In some of their early eroge, the adult content is meaningfully integrated into a thoughtful and mature storyline, though others often used it as a flimsy excuse for pornography.

Meanwhile in the arcades, Japanese developers also began producing early interactive movie laserdisc video games, the first being Sega's Astron Belt, unveiled in 1982 and released in 1983, though it was more of a shooter game presented as an action movie using full-motion video. A more story-driven interactive movie game was Bega's Battle, released in 1983, which combined shooting stages with interactive anime cutscenes, where player input had an effect on the game's branching storyline. Time Gal (1985), in addition to featuring quick time events, added a time-stopping feature where specific moments in the game involve Reika stopping time; during these moments, players are presented with a list of three options and have seven seconds to choose one.

The most famous early Japanese adventure game was the 1983 murder mystery game Portopia Serial Murder Case, developed by Yūji Horii (of Dragon Quest fame) and published by Enix. The game was viewed in a first-person perspective, followed a first-person narrative, and featured color graphics. Originally released for the PC-6001, the player interacts with the game using a verb-noun parser which requires typing precise commands with the keyboard; finding the exact words to type is considered part of the riddles that must be solved. The game featured non-linear elements, which includes travelling between different areas in a generally open world, a branching dialogue conversation system where the story develops through entering commands and receiving responses from other characters, and making choices that determine the dialogues and order of events as well as alternative outcomes, though there is only one true culprit while the others are red herrings. It also features a phone that could be used to dial any number to contact several non-player characters. The game was well received in Japan for its well-told storyline and surprising twist ending, and for allowing multiple ways to achieve objectives. Hideo Kojima praised the game for its mystery, drama, humor, 3D dungeons, for providing a proper background and explanation behind the murderer's motives, and expanding the potential of video games. The game has also been compared to the later-released Shadowgate where the player must examine and collect objects, and find their true purpose later on. According to Square Enix, Portopia was "the first real detective adventure" game.

The command selection menu input system, where the player chooses from a menu list of commands either through keyboard shortcuts or scrolling down the menu, was introduced in 1983, and would largely replace the verb-noun parser input method over the years. The earliest known title to use the command selection menu system was the Japanese adventure game Spy 007 (スパイ00.7), published in April 1983, and it was followed soon after by several other Japanese adventure games in 1983. These included the eroge title Joshiryo Panic, authored by Tadashi Makimura and published by Enix for the FM-7 in June and slightly earlier for the FM-8; Atami Onsen Adventure (熱海温泉アドベンチャー), released by Basic System (ベーシックシステム) in July for the FM-7 and slightly earlier for the PC-8001; Planet Mephius, released in July; and Tri-Dantal (トリダンタル), authored by Y. Takeshita and published by Pax Softnica for the FM-7 in August. The game that popularized the command selection system was the 1984 adventure game Okhotsk ni Kiyu: Hokkaido Rensa Satsujin Jiken (Okhotsk ni Kiyu: Hokkaido Chain Murders), designed by Yuji Horii (his second mystery adventure game after Portopia) and published by ASCII for the PC-8801 and PC-9801. Its replacement of the traditional verb-noun text parser interface with the command selection menu system would lead to the latter becoming a staple of adventure games as well as role-playing games (through Horii's 1986 hit Dragon Quest in the latter case).

Another notable adventure game released in 1983 was Planet Mephius, authored by Eiji Yokoyama and published by T&E Soft for the FM-7 in July 1983. In addition to being one of the earliest titles to use a command menu system, its key innovation was the introduction of a point-and-click interface to the genre, utilizing a cursor to interact with objects displayed on the screen. A similar point-and-click cursor interface was later used in the adventure game Wingman, released for the PC-8801 in 1984.

The NES version of Portopia Serial Murder Case was released in 1985 and became a major hit in Japan, where it sold over 700,000 copies. With no keyboard, the NES version, developed by Chunsoft, replaced the verb-noun parser of the original with a command selection menu list, which included fourteen set commands selectable with the gamepad. It also featured a cursor that can be moved on the screen using the D-pad to look for clues and hotspots, like a point-and-click interface. Horii's second adventure game Hokkaido Chain Murders was later also ported to the NES in 1987. Yuji Horii's third mystery adventure game Karuizawa Yūkai Annai (The Karuizawa Kidnapping Guide) was released for the PC-8801 in early 1985 and for the FM-7 in June that same year. It utilized the command menu system and point-and-click cursor interface of both Portopia Serial Murder Case and Hokkaido Chain Murders, in addition to introducing its own innovation: an overhead map. This gave the player direct control over the player character, who can be moved around in a top-down view to explore the area. That same year, Square's Will: The Death Trap II was one of the first animated computer games.

In 1986, Square released the science fiction adventure game Suishō no Dragon for the NES console. The game featured several innovations, including the use of animation in many of the scenes rather than still images, and an interface resembling that of a point-and-click interface for a console, like Portopia, but making use of visual icons rather than text-based ones to represent various actions. Like the NES version of Portopia, it featured a cursor that could be moved around the screen using the D-pad to examine the scenery, though the cursor in Suishō no Dragon was also used to click on the action icons. That same year saw the release of J.B. Harold Murder Club, a point-and-click graphic adventure, for the PC-98. It featured character interaction as the major gameplay element and has a similar type of multiple phrase response to more recent titles such as the adventures Shenmue and Shadow of Memories as well as the role-playing game Star Wars: Knights of the Old Republic. The TurboGrafx-CD port of J.B. Harold Murder Club was one of the first Japanese adventure games released in the United States. The J.B. Harold series went on to sell 20 million copies on various platforms as of 2011.

LucasArts (1986–2000)


In 1987 a programmer named Ron Gilbert working for the company Lucasfilm Games—which has since become LucasArts—created the script-writing system SCUMM which used a point-and-click interface similar to ICOM Simulations' MacVenture games first introduced in 1985. Instead of having to type a command to the syntax analyzer, this system was controlled by means of text icons. To interact with his environment, the player clicked on an order, on an icon representing an object in his inventory, or on a part of the image. This approach was first used by LucasArts for the game Maniac Mansion to great effect.

LucasArts would come to differentiate itself from its main competitor, the giant Sierra, by rethinking certain adventure game concepts to improve playability. Gone was the possibility to die during the course of the game and everything was done to ensure that the player was never completely stuck. Finally, LucasArts abandoned the system of points indicating the player's progress in the adventure. Many adventure games from other companies followed LucasArt's lead in these changes.

Gilbert's attempts, Maniac Mansion and Zak McKracken and the Alien Mindbenders, however, remained in 16 colors (though the FM Towns version of Zak was 256 color), and the point-and-click engine still had vestiges of text parsing, since the player would still have to construct sentences using clickable keywords combined with objects in the game. It was The Secret Of Monkey Island that was finally a complete work, with 256 colors, a more modern point-and-click engine, a dialogue system with optional responses, puzzles solved with items, original graphics, atmosphere music, and a characteristic sense of humor. Above all, the script was written as for a film (which could be done in-house) and the dialogue and inventory served the needs of the script. The 1993 release of Day of the Tentacle, a remarkable success, began a line of cartoon-style games, including the very influential Sam & Max Hit the Road as well as the acclaimed Full Throttle, which also heralded the beginning of the end of the Golden Age of adventure games.

Steven Spielberg collaborated with LucasArts in the creation of The Dig—a science fiction adventure game that the director had envisioned turning into a film.

Taking advantage of advances in action games and integrating an engine similar to those of first-person shooters, the company took a new turn in 1998 with the game Grim Fandango, where it abandoned the cartoon style and its SCUMM scripting environment for a new 3D game system named GrimE.

Following the 2000 release of Escape From Monkey Island, LucasArts would not publish another adventure game for more than eight years, canceling sequels of Full Throttle (Full Throttle: Hell on Wheels) and Sam & Max (Sam & Max: Freelance Police) that were already in development.

Japanese adventures (1987–present)
Sega's Anmitsu Hime: From Amakara Castle, released in 1987, was an adventure game with some platform game segments. The adventure game segments were puzzle-oriented and played in a side-scrolling view where the player has direct control over the character. Originally based on the Anmitsu Hime anime, an edited version based on Alex Kidd was later released in 1989 as Alex Kidd in High-Tech World. The Goonies II, also released in 1987, was a first-person adventure game with some side-scrolling action game segments. The game featured a non-linear open world environment similar to Metroid. The same year, Jiro Ishii (later known for 428: Fūsa Sareta Shibuya de and Time Travelers) released Imitation City, an adventure game with a similar cyberpunk theme to Kojima's later hit Snatcher. Another notable 1987 adventure game was Arsys Software's Reviver: The Real-Time Adventure, which introduced a real-time persistent world, where time continues to elapse, day-night cycles adjust the brightness of the screen to indicate the time of day, and certain stores and non-player characters would only be available at certain times of the day. The game also gives players direct control over the player character.

A distinct form of Japanese adventure game that eventually emerged is the visual novel, a genre that was largely inspired by Portopia Serial Murder Case, and uses many conventions that are distinct from Western adventures. They are almost universally first-person, and driven primarily by dialog. They also tend to use menu-based interactions and navigation, with point and click implementations that are quite different from Western adventure games. Inventory-based puzzles of the sort that form the basis of classic Western adventures, are quite rare. Logic puzzles like those found in Myst are likewise unusual. Because of this, Japanese visual novels tend to be streamlined, and often quite easy, relying more on storytelling than challenge to keep players interested.

Hideo Kojima (of Metal Gear fame) was inspired by Portopia to enter the video game industry, and produce his own adventure games. After completing the stealth game Metal Gear, his first graphic adventure was released by Konami the following year: Snatcher (1988), an ambitious cyberpunk detective novel graphic adventure that was highly regarded at the time for pushing the boundaries of video game storytelling, cinematic cut scenes, and mature content. It also featured a post-apocalyptic science fiction setting, an amnesiac protagonist, and some light gun shooter segments. It was praised for its graphics, soundtrack, high quality writing comparable to a novel, voice acting comparable to a film or radio drama, and in-game computer database with optional documents that flesh out the game world. The Sega CD version of Snatcher was for a long time the only major visual novel game to be released in America, where it, despite a Mature rating limiting its accessibility, gained a cult following.

Following Metal Gear 2: Solid Snake, Kojima produced his next graphic adventure, Policenauts (1994), a point-and-click adventure notable for being an early example of extensive voice recording in video games. It also featured a hard science fiction setting, a theme revolving around space exploration, a plot inspired by the ancient Japanese tale of Urashima Taro, and some occasional full-motion video cut scenes. The gameplay was largely similar to Snatcher, but with the addition of a point-and-click interface and some first-person shooter segments. Policenauts also introduced summary screens, which act to refresh the player's memory of the plot upon reloading a save, an element Kojima would later use in Metal Gear Solid. The PlayStation version of Policenauts could also read the memory card and give some easter egg dialogues if a save file of Konami's dating sim Tokimeki Memorial is present, a technique Kojima would also later use in Metal Gear Solid. From 1997 to 1999, Kojima developed the three Tokimeki Memorial Drama Series titles, which were adaptations of Tokimeki Memorial in a visual novel adventure game format.

Mirrors, released by Soft Studio Wing for the PC-8801 and FM Towns computers in 1990, featured a branching narrative, multiple endings, and audio CD music. In 1995, Human Entertainment's Clock Tower: The First Fear was a hybrid between a point-and-click graphic adventure and a survival horror game, revolving around survival against a deadly stalker known as Scissorman that chased players throughout the game. The success of Resident Evil in 1996 was followed by the release of the survival horror graphic adventures Clock Tower (Clock Tower 2) and Clock Tower II: The Struggle Within for the PlayStation. The Clock Tower games proved to be hits, capitalizing on the success of Resident Evil, though both games stayed true to the graphic-adventure gameplay of the original Clock Tower rather than following the lead of Resident Evil.

From the early 1990s, Chunsoft, the developer for the NES version of Portopia, began producing a series of acclaimed visual novels known as the Sound Novels series, which include Otogirisō (1992), Kamaitachi no Yoru (1994), Machi (1998), 428: Fūsa Sareta Shibuya de (2008), and 999: Nine Hours, Nine Persons, Nine Doors (2010). From the late 1990s, a number of Japanese adventure games began using a 3D third-person direct control format, particularly on consoles like the Dreamcast and PlayStation 2. Examples include Sega's Shenmue series (since 1999), Konami's Shadow of Memories (2001), Irem's Disaster Report series (since 2002), and Cing's Glass Rose (2003).

In recent years, Japanese visual novel games have been released in the West more frequently, particularly on the Nintendo DS handheld following the success of mystery-solving titles such as Capcom's Ace Attorney series (which began on the Game Boy Advance in 2001), Cing's Hotel Dusk series (beginning in 2006), and Level-5's Professor Layton series (beginning in 2007). English fan translations of visual novels such as Square's Radical Dreamers (a 1996 side story to the Chrono series of role-playing video games) and Key's Clannad (2004) have also been made available in recent years.

Cyan Worlds (1987–present)


Cyan, later Cyan Worlds, were among the first developers to take advantage of the CD-ROM. Their first game, a simple children's adventure game called The Manhole, became the first computer game to use the medium in 1989. In 1993, Cyan released Myst, a first-person adventure that used the extra storage capacity of the CD-ROM to include pre-rendered three-dimensional graphics, video, and audio. Despite being one of the first games to be published solely on CD-ROM, thereby requiring a CD-ROM drive, the game would go on to become highly successful.

Myst was an atypical game for the time, with no clear goals, little personal or object interaction, and a greater emphasis on exploration, and on scientific and mechanical puzzles. Part of the game's success was because it did not appear to be aimed at an adolescent male audience, but instead a mainstream adult audience. Myst held the record for computer game sales for seven years—it sold over nine million copies on all platforms—a feat not surpassed until the release of The Sims in 2000.

Decline
For much of the 1980s, adventure games were one of the most popular types of computer games produced. However, their US market share drastically declined in the mid-1990s; action games took a greater share of the US market, particularly first person shooters such as Doom and Half-Life which progressively began featuring strong, story-structured solo games. In 1990 Computer Gaming World, when discussing the state of the market, reported a "respected designer"'s statement that it was impossible to design new and more difficult adventure puzzles as fans demanded, because Scott Adams had already created them all in his early games. This slump in popularity led many publishers and developers to see adventure games as financially unfeasible in comparison. Notably, Sierra was sold to CUC International in 1998, and while still a separate studio, attempted to recreate an adventure game using 3D graphics, King's Quest: Mask of Eternity, as well as Gabriel Knight 3, both which fared poorly; the studio was subsequently closed in 1999. Similarly, LucasArts released Grim Fandango to many positive reviews but poor sales; it released one more title, Escape from Monkey Island in 2000, but subsequently stopped development of Sam & Max: Freelance Police and had no further plans for adventure games. Many of those developers for LucasArts, including Grossman and Schafer, left the company during this time. Gilbert wrote in 2005, "From first-hand experience, I can tell you that if you even utter the words 'adventure game' in a meeting with a publisher you can just pack up your spiffy concept art and leave. You'd get a better reaction by announcing that you have the plague." In 2012 Schaefer said "If I were to go to a publisher right now and pitch an adventure game, they'd laugh in my face." Text adventures met the same fate much earlier, but their simplicity has allowed them to thrive as non-commercially developed interactive fiction.

Though most commercial adventure game publication had stopped in the United States by the early 2000s, the genre was still popular in Europe. Games such as The Longest Journey by Funcom as well as Amerzone and Syberia, both conceived by Benoît Sokal and developed by Microïds, with rich classical elements of the genre still garnered high critical acclaims.

Similar to the fate of interactive fiction, conventional graphical adventure games have continued to thrive in the amateur scene. This has been most prolific with the tool Adventure Game Studio. Some notable AGS games include those by Ben Croshaw (namely the Chzo Mythos), Ben Jordan: Paranormal Investigator, Time Gentlemen, Please!, Soviet Unterzoegersdorf, Metal Dead, and AGD Interactive's Sierra adventure remakes. Adobe Flash is also a popular tool known for adventures such as MOTAS and the escape the room genre entries.

New directions
Although traditional adventure games are rare today in the US market, action-adventure games that combine elements of adventure games with action games are quite common. Sega's ambitious Shenmue (1999) attempted to redefine the adventure game genre with its realistic 3D graphics, third-person perspective, direct character control interface, sandbox open-world gameplay, quick time events, and fighting game elements. Its creator Yu Suzuki originally touted it as a new kind of adventure game, "FREE" ("Full Reactive Eyes Entertainment"), offering an unparalleled level of player freedom, giving them full reign to explore expansive interactive city environments with its own day-night cycles and changing weather, and interact with fully voiced non-player characters going about their daily routines. Despite being a commercial failure, the game was critically acclaimed and has remained influential.



There have since been a number of 3D third-person adventure games with direct character control interfaces, such as Sega's Shenmue II (2001), Konami's Shadow of Memories (2001), Irem's Disaster Report series (since 2002), Cing's Glass Rose (2003), Catherine (2011) by Atlus, and the Quantic Dream titles Omikron: The Nomad Soul (1999), Fahrenheit (Indigo Prophecy) (2005) and Heavy Rain (2010). In addition, some other adventure games have also attempted to adopt aspects of first-person shooter games in an attempt to modernize the genre, such as with Frictional Games's Penumbra series (2007–2008) and Amnesia: The Dark Descent (2010). Other examples of adventure game elements being incorporated into other genres include L.A. Noire and The Testament of Sherlock Holmes. On the other hand, other adventure games have moved away from traditional game conventions, and more closely resemble interactive stories, a major example being the visual novel genre that is popular in Japan.

There is something of a revival of the adventure game online, in both a fairly traditional style, such as the mouse-controlled text games on Rinkworks and Mystery Of Time And Space, and in 3-dimensional games, such as Crimson Room. This had led to the creation of a genre called escape the room or room-escape. Games are usually created with Adobe Flash. A parallel can be drawn with "Behind Closed Doors" by John Wilson of Zenobi Software, a popular 1980s text adventure series for the ZX Spectrum, where the object was only to escape one single location, such as a bathroom. Most of the current room-escape games consist of several locations which together make up one room.

A further resurgence in adventure games was seen due to recent changes at Lucasarts. On the first day of the 2009 Electronic Entertainment Expo, Lucasarts announced that they would be releasing both a special edition of The Secret of Monkey Island as well as working with Telltale Games to create an episodic series Tales of Monkey Island. In early July 2009, Lucasarts announced that it would supporting digital distribution of its back catalog of titles, including its classic adventure games, through services such as Steam, and has announced it will further consider porting these titles to mobile devices such as iPhones. These efforts were backed by Lucasarts' new president, Darrell Rodriguez, who has been said to be "very big on adventure games". Lucasarts has stated that digital distribution helps to remove the barrier to reproducing these titles, and hopes that they will attract a new audience to these games. The move was shortly followed by Activision who offered the King's Quest and Space Quest collections from Sierra also for digital distribution.

The Nintendo DS, with its unique touch screen and dual-screen features, has sparked a renewed interest in pure adventure game content and a resurgence in the genre's popularity, following the 2005 releases of Capcom's courtroom game Phoenix Wright: Ace Attorney (originally a 2001 Game Boy Advance game) and Cing's Another Code: Two Memories as well as the 2006 release of Cing's Hotel Dusk: Room 215. GameSpot has credited Phoenix Wright: Ace Attorney in particular for revitalizing the adventure game genre. The success of the Ace Attorney series was followed soon after by the even greater success of Level-5's Professor Layton in 2007. Both have since become some of the best-selling adventure game franchises, with Ace Attorney selling more than 4 million units worldwide and Professor Layton selling nearly 12 million units worldwide. Their success has led to an increase in Japanese adventure games, primarily visual novels, being localized for Western release, including KID's Ever 17: The Out of Infinity (2002), Hirameki's Animamundi: Dark Alchemist (2004), Irem's Raw Danger! (2006), Success Corporation's Touch Detective series (2006–2007), Marvelous Entertainment's Lux-Pain (2008), Cing's Last Window: The Secret of Cape West (2009), Chunsoft's 999: Nine Hours, Nine Persons, Nine Doors (2010), Capcom's Ghost Trick: Phantom Detective (2010), and Atlus' Catherine (2011).

Nintendo's Wii Remote is also regarded as being well-suited for the genre, and could see some ground-breaking releases in that vein for the Wii, such as Capcom's Zack & Wiki: Quest for Barbaros' Treasure (2007), Eidos Interactive's So Blonde (2008), and Cing's Another Code: R – A Journey into Lost Memories (2009). The Ace Attorney series was also ported to the Wii in 2009 and 2010. Adventure games are also seen as ideal games for mobile platforms such as the iPhone, where the use of a touch screen to interact with the game provides new directions for such games, much like the Nintendo DS. The introduction of larger and more powerful touch screen devices like the iPad are also seen as a boon to adventure games, allowing for more detailed graphics and better controls and precision over smaller touchscreen units, and a better sense of immersion and interactivity compared to personal computer or console versions. An additional avenue for the resurgence of adventure games is the downloadable game marketplace on the major consoles, including Xbox Live Arcade and Playstation Network; downloadable titles are less costly to publish and can be sold at a much lower price than a typical boxed retail product.

Telltale Games (2004-present)
Telltale Games was founded by a number of ex-LucasArts employees, including Grossman, following the cancellation of Sam & Max: Freelance Police, who sought to continue the tradition of adventure games. Their initial games were standalone titles, including a two-game series based on Jeff Smith's Bone comics, and several games based on the CSI: Crime Scene Investigation television series.

Telltale's first critically successful title was with Sam & Max: Season One, an episodic adventure game released in 2006. The game was based on the team's previous work with Freelance Police, and worked with Steve Purcell, the rights holder to the characters. The success would lead to two additional Sam & Max seasons, and subsequent deals for adventure games involving Homestar Runner, Wallace & Gromit, and Monkey Island properties. Telltale's reputation in the adventure game genre secured them a deal with Universal Studios to develop adventure titles around their properties of Back to the Future and Jurassic Park; both were met with critical success.

A subsequent licensing deal with Warner Bros. Entertainment brought the studio the rights to develop games based on Robert Kirkman's The Walking Dead and Bill Willingham's Fables comics. The first endeavor completed was the 2012 The Walking Dead video game, which had the same episodic nature as the studio's earlier games but was built more on developing characters and story and requiring the player to make significant game-changing decisions, sometimes with only a few seconds to deliberate which option to select through quick time events. The game was praised critically for its emotional story and use of the adventure genre, as well as designed its release around a timed episodic schedule. The series was named as one of the best games of 2012 from several outlets, and has won numerous gaming awards including those from the Game Developers Choice Awards, the Spike Video Game Awards, and the D.I.C.E. Interactive Achievement Awards. By release of the third episode of five, Telltale reported that at least 1.2 million unique players had purchased at least one episode; by the end of 2012, a total of 8.5 million total episodes were sold with about 25% of those on the iOS mobile platform. For Telltale, the game was considered a "goldmine", far exceeding praise and sales of their earlier titles. The success of The Walking Dead has been stated to be one of the biggest surprises for the video game industry in 2012, and a "refresh" of the adventure game genre; Ron Gilbert noted that The Walking Dead's approach to appear to the mass market can make adventure games as relevant as other genres to larger publishers. In late 2013 Telltale released The Wolf Among Us, a Fables adventure game similar to their The Walking Dead game, as well as a second season of The Walking Dead, and would later announced additional licensed titles, including one based on the A Song of Ice and Fire/Game of Thrones high fantasy series, and on the Borderlands video game series.

Double Fine Productions and genre growth by crowdfunding (2000-present)
Double Fine Productions was created by Tim Schafer shortly after his departure from LucasArts. Like Telltale, the development team includes several former LucasArts adventure game programmers.

Double Fine's first two games, Psychonauts and Brutal Legend, were praised critically by game journalists but were not considered financial successes for the company. During the troubled development of Brutal Legend, Schafer had instituted yearly "Amnesia Fortnights", where the entire team would be told to drop their current duties, split into teams, and work at developing prototypes of new games, as to help employee morale. Without a publishing contract following Brutal Legend's release, Schafer turned back to these prototypes and was able to secure four for publishing deals. Two of these, Costume Quest and Stacking, employ elements of adventure games, such as Stacking's use of matryoshka dolls to act as both inventory and "verbs" to act on such items.

Double Fine ran a Kickstarter campaign in early 2012 to develop a traditional point-and-click adventure game title, tentatively titled Double Fine Adventure and now officially called Broken Age; Schafer had seen the Kickstarter model ideal for pitching a new adventure title directly to those who would buy it, as he found that publishers would refuse to consider the idea of publishing adventure games at that time. Double Fine had set a modest goal of $400,000 - $300,000 to develop the game with a budget comparable to many mobile games, and the remaining for a documentary of the development created by 2 Player Productions. The initial funding amount was met within hours of going live, and the Kickstarter ended with $3.45 million, far exceeding Double Fine's expectations. The company will use the additional funds to expand the platforms and languages available, to include voice acting, and other improvements.

Double Fine's success was widely covered by the gaming media, and immediately drew attention to the Kickstarter platform. This proved especially attractive to other designers of adventure games, many of whom had drifted away from the genre for similar reasons to Schafer. In the two years following Double Fine's campaign, many sequels, remakes, and spiritual successors to classic adventure games emerged on Kickstarter, leading to a significant increase in traditional adventure game development during this time. Some of these include:


 * Armikrog
 * Broken Sword: The Serpent's Curse
 * Dreamfall Chapters
 * Gabriel Knight
 * Leisure Suit Larry: Reloaded
 * Moebius: Empire Rising
 * Obduction
 * SpaceVenture
 * Tesla Effect: A Tex Murphy Adventure

Double Fine also hired Ron Gilbert for his own project, The Cave, a hybrid adventure and platforming game.

Sierra Entertainment (2014-present)
In August 2014, Sierra Entertainment, a pioneer of the graphic adventure genre, was revived as a publisher by its parent company, Activision Blizzard, and it was announced that among Sierra's first projects would be a new entry in the King's Quest series, developed by The Odd Gentlemen, and that the game would be a pure adventure game.

Emulation
Many classic adventure games cannot run on modern operating systems. Early adventure games were developed for home computers that are not in use today. Emulators are available for modern computers that allow these old games to be played on the latest operating systems. One Open Source project called ScummVM provides a free engine for the LucasArts adventure games, the SCUMM-derived engine for Humongous Entertainment adventure games, early Sierra titles, Revolution Software 2D adventures, Coktel Vision adventure games and a few more assorted 2D adventures. Another called VDMSound can emulate the old sound-cards which many of the games require.

One of the most popular emulators, DOSBox, is designed to emulate an IBM PC compatible computer running MS-DOS, the native OS of most older adventure games. Many companies, such as Sierra Entertainment, have included DOSBox in their re-releases of older titles.

Text adventure games are more accessible. There are only a small number of standard formats, and nearly all the classics can be played on modern computers. A popular text adventure interpreter is Frotz, which can play all the old Infocom text adventures. Some modern text adventure games can even be played on very old computer systems. Text adventure games are also suitable for PDAs, because they have very small computer system requirements. Other text adventure games are completely playable via web browsers.