Poison is a status in Final Fantasy IV. The Poison status is timed. A high Stamina stat or a high max HP (monsters only) will reduce the duration of this status. Haste accelerates the effect, while Slow delays it. When the timer has elapsed, damage from Poison is dealt to the afflicted target. The timer can be reset by recasting the spell Poison spell. Poison ignores priority and can be set even if higher-priority status effects, except KO or Petrify, are already present.
Target's inflicted by Poison will lose 1/8 of their HP during battle when the timer for this status has elapsed with minimum damage dealt is 1. The target cannot die outside of battle due to Poison has the character will be stuck at 1 HP. Every step taken will also make the screen blurs for a few seconds, similar to using a mosaic effect. Casting Teleport while someone is under this status will at most lose 42 HP, but this is only applicable in the SNES version.
Since Poison resistance wasn't fixed until the GBA port in the Euro or Jap 1.1 version, it will stick onto pretty much any target, excluding those that have the boss bit.
