Some abilities modify the statistics of their target. Abilities that increase a target’s statistics are called buffs, while abilities that decrease their statistics are called debuffs. When you use a buff or debuff on a character, it does not increase or reduce the statistic directly. Instead, it moves that statistic up and down something called the Bonus Tracker. By default, the bonus to each of a character’s statistics is +0. A single level of buff applied to that statistic gives it a bonus of +1 for the duration of the battle. Another level raises this bonus to +3, and the final level raises it to +7. Subsequent buffs do nothing. Likewise, a single level of a debuff on a statistic imposes a penalty of -1, a second level imposes a penalty of -3, and a third will impose a penalty of -7. Further debuffs do nothing. In addition, buffs and debuffs are capable of cancelling each other out. One level of buff will cancel out one level of debuff, and vice versa.
Another way of putting the above is that each level of buff raises the statistic one level up the Bonus Tracker, and each level of debuff lowers the statistic one level down. There are seven levels on the Bonus Tracker in total, corresponding to additive modifiers of -7, -3, -1, +0, +1, +3, and +7. All character statistics start in the middle of the Bonus Tracker at +0, and return to the middle at the end of every battle. Buffs and debuffs cannot be resisted, although some passive equipment bonuses and monster abilities will render a character immune to certain buffs and/or debuffs. Character statistics can be buffed and debuffed to any numerical value.