Thunder Slash glitch

The Thunder Slash glitch involves the skill Thunder Slash in Final Fantasy IX. Thunder Slash's base accuracy is set to 0 with a Gravity magic-type effect and as a result, Thunder Slash is almost completely worthless. Though Final Fantasy IX has seen various re-releases, the glitch has never been fixed.
If the magic and level of Steiner (or Beatrix) are high enough compared to the target's level, the skill has a chance to hit, as the hit rate formula is Magic / 4 + Level - TargetLevel.
There is a second check after this for the target's magic evasion.
There has been various speculation on the bug's origin. A prevailing theory is that Thunder Slash had its Effect code swapped with its damage multiplier code. The effect code error would have caused the ability to deal fractional damage instead of weapon-based damage, but instead of using the weapon's Accuracy value, it must use the ability's own Accuracy value, which is 0%.
It is possible that Thunder Slash was not supposed to deal fractional damage (19% of the target's max HP), but rather, do x1.9 of normal damage with an added Lightning element. The value for a physical attack ability is "19", and the code for a proportional damage ability is "17". If the damage multiplier were re-swapped with the Effect code, the multiplier would result in x1.7 of the normal damage with an added Lightning element. It is also possible that Thunder Slash was changed into a fractional damage ability intentionally, because Steiner already had a Thunder-based sword skill via Sword Magic, but the Accuracy value was mistakenly left at 0%.
Beatrix's Thunder Slash when she is fought as a boss works, dealing moderate Thunder damage to a target.
==References==
Category:Bugs in Final Fantasy IX