Blue Archive – Buff / Debuff Stacking Rules

Buff / Debuff Stacking Rules / Mechanic

Buffs/debuffs on the same stat type will overwrite older same-slot occupying buff/debuff even if the new one is weaker in effect.

To understand what “slot” a buff/debuff will occupy:

General / Casual Understanding

You can consider the combinations of SKILL SOURCE + TARGETING TYPE as available slots on a target for buffs and debuffs on the same stat type:

• Skill Source — EX, Normal/Basic (NS), Passive/Enhanced (PS), Passive+/Enhanced+ (PS+), Sub (SS)
• +
• Targeting Type — Self-only, Targetable, Aura

So a target can potentially have up to 5 x 3 = 15 buff and debuff slots available for one stat type. (don’t get this mixed up with actual buff/debuff self-stacking mechanism such as Natsu’s sub skill that explicitly says “can stack up to 3 times”)

Examples:

1. Akane EX is a single-target DEF% debuffing skill. This would fall under EX + Targetable debuff slot for DEF% on the enemy target
2. Serika EX is a self-only ATK% buffing skill. This would fall under EX + Self-only buff slot for ATK% on herself
3. Natsu Normal/Basic skill is a multi-ally targeting ATK% buffing skill. This would fall under NS + Targetable buff slot for ATK% on the affected allies
4. Hoshino (Swimsuit) EX generates an aura around her that buffs ATK% and “Explosive Effectiveness” to any allies within the circle. This would fall under EX + Aura buff slots for ATK% and Explosive Effectiveness on herself as well as any affected allies

Exceptions / Quirks:

1. TSS/Special summoning units like Sena or Miku creates a new unit that provides a buff aura. This aura actually falls under Passive/Enhanced skill source.

It’s easy to confuse this but consider the Special unit’s EX as the summoning act, and the summoned unit is its own entity that has the aura as its passive.

2. Furthermore on TSS units, the summoned units generally receive inherited stat buff based on % of summoner’s stat and EX skill level. This particular buff is unique in a way that technically it’s coming from the summoner as EX + Targetable, but the end result is its own flat-value buff instead of % stat that don’t occupy that slot.

Example: Iroha EX summons Toramaru tank with the inherited ATK as its own buff when spawned. This buff ends up being flat ATK value from inheritance, and so it stacks with buff from Kotama EX which would be EX + Targetable buff slot for ATK%.

It’s hard to say whether this is because it’s not occupying the same stat (e.g. flat ATK and ATK% are two different stat types), or if the inheritance buff has its own separate but unknown channel value (more on “channel” under Advanced/Technical Explanation).

3. The cost reduction buffs from Ui EX and Kokona’s Sub skills technically should have stacked with each other, but they don’t. This is more than likely a limitation on the cost reducing mechanic in the game, so they will end up overwriting each other instead.