Rubberband AI

Rubberband AI (sometimes known as "catch-up") is a simple form of artificial intelligence that is used in most racing and sports video games, in particular, those of the "kart racing" genre. It is used to give games a challenge level that adapts to the skill of the player, making opposing computer-controlled opponents less competitive when the player falls behind or more competitive when the player takes the lead. The technique has little to do with complex "intelligence" and more to do with formulaic adjustment of the computer player's performance. The word "rubberband" relates the technique to the idea of two or more things being held or kept close together by a rubber band.

In racing games, rubberband AI involves increasing or decreasing the speed of opponents' vehicles. If the player falls behind, the opposing cars will slow down, giving the player some ability to catch up and remain competitive. If the player takes the lead, the opposing cars will speed up, often exceeding their stated top speed, preventing the player from achieving an insurmountable lead. The technique is often used in kart and combat racing games, most of which feature weapons used to attack other drivers. As such, it prevents players in the lead from putting enough distance between themselves and trailing opponents to get out of firing range. As a result, players are often punished for good racing skills, the game instead favoring combat skills or pure luck. Often the best tactic is to simply drive safely through the bulk of the race, saving up weapons and turbos (if available), then going all out on the last lap or final stretch of the race. This essentially makes the majority of the race meaningless, and is a major criticism of rubberband AI. Note that this does not only apply to CPU opponents; multiplayer games also often use the rubberband effect to keep the race close. While the technique may keep a race consistently exciting, the same criticisms apply as it may cause the technically better player to lose because of an unfair handicap.

Many critics also point out that rubberband AI is an undocumented feature of more "legitimate" titles such as the "Madden NFL" football series. In such cases the rubberband AI is unobvious, i.e. it gives players the false impression that they are enjoying a fair match.

Forms

One form of rubberband AI also has the computer-controlled cars trying to finish the race in a certain order; if one car has a spill and falls back a few places, it will speed up in order to regain its position, and other cars will allow it to pass instead of trying to keep their new positions. In games that feature a circuit style tournament, points are awarded based on the ranks that each car finishes in. By having the cars finish in a particular order, a favored car collects the most points, forcing the player to win most — if not all — of the races in order to win the circuit. If a favored car has a spill near the end of the race, causing it to drop in the point standings, the AI will change to favor the cars that overtake the lagging vehicle in the standings. Therefore, whoever has the most points will try to finish first. In essence, all the computer-controlled cars conspire against the player by helping one specific opponent win most of the races and gain more points in the standings.

As mentioned above, rubberband AI can also be found in some arcade-style sports games as well. Sports game rubberband AI works by either altering the abilities or skills of the teams involved or by causing a higher-than-probable number of occurrences of a potentially game-breaking event (a timely turnover or injury).It should be noted that this feature can be turned off in some games. For example, the arcade version of "NBA Hangtime" allowed the operator to disable rubberband AI in order to allow for a result based on skill alone.

Cheating AI

Cheating AI is a term used to describe the situation where the AI has regularly impossible advantages over the player(s), including faster, stronger, or more damaging attributes. It is typically used in games to artificially increase the difficulty of the game, because humans generally use more intelligent strategies than the AI, and could defeat it easily if it were not for these advantages. Cheating AI is a unique form of rubberband AI, in that in such situations the computer ignores certain boundaries that player(s) must abide by to give itself an advantage.

A common example of this is found in many racing games. The computer-controlled cars will, in most cases, already have upgraded attributes well before the player. AI cars may also respawn quicker (in most car-combat games), or have significantly better powerups unavailable to the player. Alternatively, in real-time strategy games such as the "Command & Conquer" series, the AI is able to gather resources and/or build weapons faster than the human player, allowing it to field a large army before its opponent has even finished building his/her base.

Critics claim that using this technique discourages developers from programming more human-like bots, giving them the easy alternative of letting the AI cheat. However, cheating AI may also be implemented as a player-selectable option, to increase the level of challenge, and thus increase the longevity of the game, once the player has exhausted the limits of the AI's base ability.

External links

* [http://tvtropes.org/pmwiki/pmwiki.php/Main/RubberBandAI "Rubber Band AI" on TV Tropes Wiki, containing several examples]