|This art~cle conta8%5uè[f$ated for M.U.G.E.N multiple time89^f6!|
|This article contains information about a glitch or bug in the M.U.G.E.N engine and is not guaranteed to still be present in future updates.|
Poison is an effect that is common in many games, most noticeably RPG games. While poison is typically uncommon in fighting games, the first noticeable example of a character that can inflict poison on an opponent is Shiki from Samurai Showdown.
A character that is poisoned will slowly have their health drained over time. Normally, this effect is not possible outside of a fullgame environment in M.U.G.E.N without repeatedly hitting the opponent. However, a poison effect can be accomplished by taking advantage of a glitch in M.U.G.E.N's Reversaldef controller. The first character in M.U.G.E.N to utilize this glitch was Umbreon by ShowBuySpirit.
The glitch explained
Normally, when player 1 hits player 2 with an attack, the M.U.G.E.N engine forces player 1 to keep track of player 2's as a "target". This allows player 1 to use certain triggers and state controllers, such as the "target" redirection trigger and the "TargetState" state controller. Normally, when player 2 returns to a non-hit state, such as their idle state (standing state), all target IDs are dropped from player 1. However, if player 2 is hit by a Reversaldef state controller from player 1, player 1 will retain player 2's target information, even after they return to their idle state. This allows player 1 to continue to use controllers such as TargetState and TargetLifeAdd on player 2, even when they are no longer a target.
The Poison "glitch" typically involves player 1's attack placing player 2 in a custom state, along with a helper bound to player 2 that contains a Reversaldef state controller and a red hitbox. This custom state is coded as an attack state using an uncommon attack type, such as "C,HT" (Crouching Hyper Throw), while the Reversaldef in the helper's state is set up to only activate on attacks of that same type. Once player 2 returns to their idle state, the helper continues to track player 2 as a target, using the TargetLifeAdd controller to gradually drain health from player 2, simulating the effect of poison.