Beneficial and Harmful Effects¶

Terminology¶

Unfortunately Com2uS' terminology is a bit inconsistent. When they say beneficial and harmful effects, they usually mean only buffs and debuffs (the blue/red icons over your monsters in battle). But not always, for example the immunity buff says it prevents all harmful effects but it does not just block debuffs but also attack bar (ATB) reduction and cooldown increases. So in this wiki we use the following explicit notation:

Buff means any in-battle positive effect that has a blue icon.
Debuff means any in-battle negative effect that has a red icon.
Beneficial effect means buff, ATB increase, or cooldown reduction.
Harmful effect means any debuff, ATB reduction, or cooldown increase.

Attention

The counterpart to immunity, the "Beneficial Effects Blocked" debuff, does not prevent attack bar increase or cooldown reduction from happening. It only prevents buffs from being applied. This slight imbalance is a deliberate game design choice from Com2uS in order to not make it too easy to completely destroy AI controlled defences even though both of those effects are beneficial in almost all cases. But it does create some of the inconsistencies in the naming in the game.

Tip

Up to 10 (de)buffs can be applied on a single monster. If a (de)buff is applied again, the one applied last will replace the existing effect (but only if it is better or equal, e.g. the stronger shield prevails or a buff for more turns). The only eceptions to this are Continuous Damage, Bomb, and Recovery effects which can be accumulated.

Beneficial Effects¶

Buffs¶

Here is an overview over the buffs currently in the game:

Buff Icon	Buff Name	Buff Effect (Com2uS description)
	Increase ATK	The target's Attack Power will be increased by 50%.
	Increase DEF	The target's Defense increased by 70%.
	Increase ATK SPD	The target's Attack Speed will be increased by 30%.
	Increase CRI Rate	The target's Critical Rate will be increased by 30%.
	Increased CRI Resist	Decreases the chances of being attacked with a Critical Hit by 50%.
	Immunity	The target will gain immunity against all harmful effects.
	Reflect DMG	The target will return 30% of the incoming damage to the attacker when attacked.
	Recovery	The target's HP will be recovered by 15% on each turn.
	Vampire	Recovers HP by 20% of the inflicted damage.
	Shield	The Shield will absorb a fixed amount of damage.
	Shield	A Rune Shield will be created on all allies, absorbing 15% of the HP of the Monster equipped with a set of 2 Shield Runes. (The Rune Shield will absorb more damage when more than 1 set is equipped.)
	Counter	When attacked, the target will counterattack to inflict 75% of the Attack Power as damage.
	Defend	The caster of this skill will receive half of the damage inflicted on the escorted target while making the damage dealt to the escorted target to 0 and counterattack the enemy target.
	Endure	The target's HP will not drop below 1 even when attacked.
	Soul Protection	The target will revive with 30% HP when defeated.
	Invincible	The target will be invincible.
	Threat	The enemy can only attack the target under the Threat state when using the attack skill. The target under the Threat state will be inflicted with 15% less damage when attacked.
	Reflect Harmful Effect	Reflects harmful effects granted on the Monster excluding inability effects.

Notes

Increase DEF, CRI Resist, Shield, Shield (Rune), Reflect DMG, Invincibility, and Defend count as damage reduction effects which can be ignored by some skills. Endure however does not prevent damage, just death.
The shield from the rune set is calculated off base HP and stacks even across different monsters. E.g. 1 set on a 10k base HP monster and 1 on a 5k base HP monster will net you a 2250 shield in total.
Unlike the other buffs the counter on Threat state counts down on being hit, not on the monster taking a turn.
Lifesteal is limited to 100%.
SPD values in the game are rounded only once. A SPD (de)buff is applied to the pre-rounded SPD value instead of the rounded one, after that the rounding takes place. See attack bar for more info.
A stat changing buff and the corresponding debuff cancel eachother out instead of being multiplied. This means with an ATK buff and debuff your monster acts like it has none of it.

Harmful Effects¶

Debuffs¶

Here is an overview over the debuffs currently in the game:

Debuff Icon	Debuff Name	Debuff Effect (Com2uS description)
	Decrease ATK	The target's Attack Power will be decreased by 50%.
	Decrease DEF	The target's Defense will be decreased by 70%.
	Decrease ATK SPD	The target's Attack Speed will be decreased by 30%.
	Stun	The target will be stunned and won't be able to attack.
	Freeze	The target will be frozen and won't be able to attack.
	Sleep	The target will be put to sleep and won't be able to attack. The sleeping target wakes up when attacked or inflicted with damage.
	Continuous DMG (dot)	The target's HP will be damaged by 5% of the MAX HP whenever the target's turn returns. (Ignores Defense)
	Bomb	Explodes after a fixed amount of turns to inflict damage and stuns the target for 1 turn. (Ignores Defense)
	Unrecoverable	The target's HP can't be recovered.
	Beneficial Effects Blocked	All beneficial effects will be blocked.
	Increased chances of missing	The chances of landing a glancing hit will be increased by 50%. (Glancing Hits will decrease the damage by 30% and if the attacker has Attribute disadvantage, damage will be decreased additionally by 16%.)
	Provoke	The target is forced to attack the Monster that provoked it.
	Silence	Skills with cooldown will be locked. (Passive skills not included)
	Brand	The target will receive 25% increased damage.
	Oblivion	Passive skills will be locked.
	Harmful Effect Removal Blocked (HERB)	Harmful effects cannot be removed while this effect is on. This effect will be removed first when the harmful effect removal skill is used, an other harmful effects can be removed afterwards.
	Suppression	The HP is reduced by 50% of MAX HP if the target uses a skill with cooldown time. (Ignores Defense) Suppression is removed once this effect is activated.
	Seal	Deactivates set effects of Despair, Vampire, Violent, Nemesis, Revenge, Destroy, and Seal Runes.
	Irresistible	The target under Irresistible cannot resist any types of harmful effects.

Notes

The three inability effects Stun, Freeze, and Sleep will prevent a monster's cooldowns from counting down.
"Block Beneficial Effects" does not prevent ATB increase or cooldown reduction.
Silence acts like skills are on cooldown so Rakan can revenge when being silenced even if his S3 is technically up.
Oblivion does not reset stacks on passives, it just temporarily disables them. Also it has no effect on passives that happen once before the battle begins (e.g. Leona, Iron).
Monsters gaining effects when attacking monsters under certain debuffs still get the effect even when it wasn't inflicted by them.
HP balancing skills such as Chasun's "Fallen Blossom" can bypass the Unrecoverable debuff because they do not technically heal.
Bombs and Continuous Damage do not just ignore defence, they actually deal true and pure damage, respectively. See damage types for more info.
Inability effects inflicted during the monster's turn (e.g. Tablo's self-stun) can not be procced out of.
2-turn inability effects also prevent violent procs in general.
SPD values in the game are rounded only once. A SPD (de)buff is applied to the pre-rounded SPD value instead of the rounded one, after that the rounding takes place. See TODO for more info.
A stat changing buff and the corresponding debuff cancel eachother out instead of being multiplicate. E.g. with an ATK buff and debuff your monster acts like it has none of it.
Due to Com2uS' lazy implementation of her S3 the HERB debuff also prevents Tiana from working as intended.

Fun Fact

Freeze is identical to stun when it comes to game play. The only difference is that only water monsters have the Freeze debuff and it prevents the little victory dance animation at the end of battle while stunned or sleeping monsters still perform that.

Harmful Effect Application¶

In order to apply any harmful effect, two stages have to be passed:

Activation stage
Accuracy vs. Resistance check (ACC/RES check)

The activation stage is simply a check if the monster even tries to apply a harmful effect. The activation rate is given in the skill description, for example Alicia's S3 will try to freeze with a 15% chance (per hit). If no explicit probability is given, the activation rate is 100% and this stage automatically passes.

If the activation stage is passed then a monster tries to apply a harmful effect. If that happens is then determined by the ACC/RES check explained in detail below. If both stages are passed, then the debuff is applied.

Notes

This describes the normal process, some skills bypass the ACC/RES check by being irresistible.
The stun applied by Despair runes does not have an ACC/RES check
Even though it is not a harmful effect the process of removing buffs (called a "strip") also goes through the same stages.
If a hit glances, it will not apply any debuffs or ATB reduction. However, cooldown resets and stripping can still happen.

Accuracy versus Resistance Check¶

As you can see in this screenshot, the game directly explains how accuracy and resistance are interacting with eachother. Put into a formula it is with $p_{resist}$ being the chance to resist a debuff and $~p_{apply}~$ the chance of the debuff being applied:

$p_{resist} = \max(ACC - RES, 15\%)$

or

$p_{apply} = 1 - p_{resist} = 1 - \max(ACC - RES, 15\%)$

Attention

This directly means that anything above 85% is no different from 85% so you only need 85% ACC at most to achieve the highest rate of landing your debuffs in any content, including PvP.

Below is an illustration of how the chance to resist an effect looks like for selected RES values.

As you can directly see from the formulas above you only need RES - 15% ACC to reach the maximum chance of landing your debuff. Here is a table with the maximum resistance values found in several PvE areas:

Area	Maximum RES	ACC cap
ToA(H)	60%	45%
ToA Hell	70%	55%
GB12	70%	55%
DB12	80%	65%
NB12	70%	55%
SB10	40%	25%
PB10	54%	39%
R5	30%	15%
Dimension Hole	49%	34%

Attention

Prior to patch 6.4.6 the Giant's Keep mid boss had 100% RES for ridiculous historical reasons which meant that technically 85% ACC was required on important debuffers. If you see this being mention in guides and are wondering why it contradicts the info in the table above it is because those guides have not been updated.