More recently game designers have attempted to encourage emergent play by providing tools to players such as placing web browsers within the game engine (such as in EVE Online, The Matrix Online), providing XML integration tools and programming languages (Second Life), fixing exchange rates (Entropia Universe), and allowing a player to spawn any object that they desire to solve a puzzle (Scribblenauts).
Intentional emergence 
Intentional emergence occurs when some creative uses of the game are intended by the game designers. Since the 1970s and 1980s board games and table top role playing games such as Cosmic Encounter or Dungeons & Dragons have featured intentional emergence as a primary game function by supplying players with relatively simple rules or frameworks for play that intentionally encouraged them to explore creative strategies or interactions and exploit them toward victory or goal achievement.
Creative solutions 
In games with complex physics and flexible object interaction it may be possible to complete in-game problems using solutions that the game designers did not foresee. Deus Ex is often cited as a game responsible for promoting the idea of emergent gameplay, with players developing interesting solutions such as using wall-mounted mines as pitons for climbing walls.
Such emergence may also occur in games through open-ended gameplay and sheer weight of simulated content, in Dwarf Fortress for example. The Nintendo DS game Scribblenauts allows the player to write the name of tens of thousands of nouns within its database to bring that object into a game's level and have it behave realistically within the game's engine; the game challenges the player to find as many ways to complete puzzles or reach a goal by using such objects in any combination, and is considered by its developers 5TH Cell to promote emergent gameplay.
Emergent narrative 
Some rare games don't use a pre-planned story structure, even non linear.
In The Sims, a story may emerge from the actions of the player. But the player is given so much control that they are more creating a story than interacting with a story. Emergent narrative would only partially be created by the player. Warren Spector, the designer of Deus Ex, has argued that emergent narrative lacks the emotional impact of linear storytelling.
Left 4 Dead features a dynamic system for game dramatics, pacing, and difficulty called the Director. The way the Director works is called "Procedural narrative": instead of having a difficulty which increases to a constant level, the A.I. analyzes how the players fared in the game so far, and tries to add subsequent events that would give them a sense of narrative.
Unintentional emergence 
Unintentional emergence occur when creative uses of the video game were not intended by the game designers.
Using game glitches 
Emergent gameplay can arise from a game's AI performing actions or creating effects unexpected by even the software developers. This may be by either a software glitch, the game working normally but producing unexpected results when played in an abnormal way or software that allows for AI development; for example the unplanned genetic diseases that can occur in the Creatures series.
Glitch or quirk-based strategies 
In several games, especially first-person shooters, game glitches or physics quirks can become viable strategies, or even spawn their own game types. In id Software's Quake series, rocket jumping and strafe-jumping are two such examples. In the game Halo 2, pressing the melee attack button (B) quickly followed by the reload button (X) and the primary fire button (R trigger) would result in the player not having to wait for the gun to be back in position to shoot after a melée attack. Doing this has become known as "BXR-ing". Starsiege: Tribes had a glitch in the physics engine which allowed players to "ski" up and down steep slopes by rapidly pressing the jump key, gaining substantial speed in the process. The exploitation of this glitch became central to the gameplay, supplanting the vehicles that had been originally envisioned by the designers as the primary means of traversing large maps.
Thanks to a programming oversight by Capcom, the combo (or 2-1 combo) notion was introduced with the fighting game Street Fighter II, when skilled players learned that they could combine several attacks that left no time for their opponents to recover, as long as they were timed correctly.
Changing game objectives 
In online car racing games, particularly Project Gotham Racing, players came up with this variation. The racers play on teams of at least two cars. Each team picks one very slow car as the mouse, and their goal is to have their slow car cross the finish line first. Thus the team members in faster cars aim to push their slow car into the lead and ram their opposing teams' slow cars off the road.
Completing games without getting certain items or by skipping seemingly required portions of gameplay result in sequence breaking, a technique that has developed its own dedicated community. Often, speed of completion and/or minimalist use of items are respectable achievements. This technique has long been used in the Metroid game series and has developed into a community devoted to speedruns. NetHack has over time codified many such challenges as "conduct" and acknowledges players who manage to finish characters with unbroken pacifist or vegetarian disciplines, for example.
Machinima, the use of computer animation from video game engines to create films, began in 1996. The practice of recording deathmatches in id Software's 1996 computer game Quake was extended by adding a narrative, thus changing the objective from winning to creating a film. Later, game developers provided increased support for creating machinima; for example, Lionhead Studios' 2005 game The Movies, is tailored for it.
Real economy interaction 
Traders in massively multiplayer online games with economic systems play purely to acquire virtual game objects or avatars which they then sell for real-world money on auction websites or game currency exchange sites. This results in the trader's play objective to make real money regardless of the original game designer's objectives.
Many games prohibit currency trading in the end-user license agreement (EULA), but it is still a common practice.
Some players provide real world services (like website design, web hosting) paid for with in-game currency. This can influence the economy of the game, as players gain wealth/power in the game unrelated to game events. For example, this strategy is used in Blizzard Entertainment's World of Warcraft.
Gambling and lotteries may occur in online role-playing games such as EVE Online and Dark Age of Camelot. The provision of gambling services in exchange for in-game currency can take the forms of a lottery, card games, event betting, or any number of other variations, most often at least loosely based on established real-world games. Players typically establish a betting facility, lottery etc. Players typically create a website for executing the gambling, then accept payment from gamblers using in-game currency to credit the gambler's website account. Winnings are then paid back to the gambler's account. Other forms of gambling are commonly used in Massively Multiplayer Online Games, such as betting on who will win a duel.
Game financial institutions 
In games with no financial law game mechanism, players develop financial institutions. Forms include banks or investment schemes launched with an Initial public offering, typically based purely on trust.
The world's first MMORPG IPO was ISS Marginis by the Interstellar Starbase Syndicate (ISS) in Eve-Online, on 29 September 2005. This was for a dividend based on profitability. The ISS followed up with a series of IPOs, culminating in an IPO of the player guild itself promising a fixed return, like a bond. Eve Online has no game-mechanism for financial law.
In games with rough economies like World of Warcraft's Auction House system, some players make a living by buying items that are unusually low priced and reselling them at high prices, or by buying out all competition and creating a monopoly. In the MMO Runescape, players can purchase many thousand units of an item then sell them later for a profit just like a normal commodity market. This game includes price data on all items for the last 180 days.
Emergent gameplay appears when there is good game simulation according to Peter Molyneux, creator of Populous and other games. Simulated worlds allow players to play around the world and should respond realistically to player’s actions. This is what made SimCity and The Sims compelling to people. Similarly, being able to freely interact with the city’s inhabitants in the Grand Theft Auto series adds an extra dimension to the games.
The following is an example of emergent gameplay Molyneux gave with his game, Fable:
He says he watched a 15-year-old play tester chat up a woman in town who happened to be the mayor's daughter. He brought her gifts and flowers, talked to her all the time, started hugging and kissing her... and eventually they married and moved in together. Molyneux says he was delighted that a player was exploring this part of the game. Then the playtester talked to the Mayor and asked him to follow him. He took the mayor out to the woods, got him behind a tree ... and killed him! "Why did you do that!?" Molyneux asked. "I figured the mayor was rich, and he'd give all his money to his only daughter," answered the tester. Of course, now the daughter had lots of money, but didn't want to share any of it. So the playtester killed her, too. Then he moved into the mayor's house!
See also 
- Procedural generation#Software_examples
- Alternate reality game
- Corrupted Blood incident
- Sandbox game
- Rom hacking
- Game Genie
- Cellular automaton, a 0-player "game" that can produce various emergent patterns
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- "Deus Ex designer Harvey Smith discusses emergent gameplay". IGDA. Archived from the original on 2011-07-22.
- Allen Tan (July 10, 2008). "Indie Treasures: Dwarf Fortress". brighthub.com. Retrieved 2008-11-20. "There's so much content that is simulated in the game that emergent gameplay finally has a meaning."
- "World Debut: Scribblenauts". IGN.com. 2008-12-05. Retrieved 2008-12-06.
- Rollings, Andrew; Ernest Adams (2006). Fundamentals of Game Design. Prentice Hall. pp. 194–204. ISBN 0-13-168747-6.
- "GDC 2004: Warren Spector Talks Games Narrative". Xbox.ign.com. Retrieved 2009-09-16.
- Newell, Gabe (2008-11-21). "Gabe Newell Writes for Edge". edge-online.com. Retrieved 2008-11-22. "The events are trying to give them a sense of narrative. We look at sequences of events and try to take what their actions are to generate new sequences. If they've been particularly challenged by one kind of creature then we can use that information to make decisions about how we use that creature in subsequent encounters. This is what makes procedural narrative more of a story-telling device than, say, a simple difficulty mechanism."
- Kline, Dan (2009-01-03). "Procedural Narrative: Left 4 Dead". Retrieved 2009-05-10. "The horror setting, the tight team dynamic and situations, the swaying difficulty, the orthogonally designed super-zombies, all compound to push the players alongside the pacing and set up dramatic conflict and hard, human choices. As opposed to hard, systematic choices. Even though there’s barely a traditional “narrative” at all in L4D, the mechanics and the experience manager seem to create a framework that allows the player’s to build their own unique story, but in a different way then the Sim and Civilization-likes designers refer to it. This is player story built on structure, rather than player story built in a sandbox. And we know from experience that structured storytelling creates something special"
- "The Origin of CyberLife: An interview with Steve Grand by Sue Wilcox" retrieved from biota.org, in which Grand discusses emergence.
- Butts, Steve. "Tribes: Vengeance Review". IGN. Retrieved 2009-09-07.
- "The Essential 50, Part 32: Street Fighter II". 1up.com. 2009-08-13. Retrieved 2009-09-16.
- Lowood, Henry (2005). "Real-Time Performance: Machinima and Game Studies" (PDF). The International Digital Media & Arts Association Journal 2 (1). 13. ISSN 1554-0405. Archived from the original on 2006-08-23. Retrieved 2006-08-07. "no"
- Sotamaa, Olli (2007). "Let Me Take You to The Movies: Productive Players, Commodification and Transformative Play". Convergence: the International Journal of Research into New Media Technologies (Sage Publications) 13 (4): 383. doi:10.1177/1354856507081961. More than one of
- Sotamaa, Olli (2007). "Let Me Take You to The Movies: Productive Players, Commodification and Transformative Play". Convergence: the International Journal of Research into New Media Technologies (Sage Publications) 13 (4): 392–393 . doi:10.1177/1354856507081961. More than one of
- "ISS Marginis, worlds first MMOG IPO".
- "Interstellar Starbase Syndicate - Player Guild IPO".
- RuneScape Grand Exchange
- Kosak, Dave (2004-03-07). "The Future of Games from a Design Perspective". gamespy.com.