Each negative effect in the game has a description attribute — a marker used by the game to determine which resistance a target can use to protect itself from it. Mental Shield raises exactly three of these:

Skills available to players. "Base Chance" is the starting point for calculations; in combat, it's already modified by multipliers. Note that some mental effects are physical abilities, not spells:

Resistance isn't subtracted from the percentage chance—it's included in the fraction. The attribute multiplier is calculated as follows:

Players in this chronicle receive virtually no effect power: the indicator is in the code, but there are no sources to access. The only exception is sharpening: it adds power to mental skills (and only to them, sleep and hold do not receive anything from sharpening), maximum +40.

Hence, a simple form of the formula for the usual case: (90 − resistance) ÷ 60Two conclusions follow from this that overturn the usual understanding of the buff.

First. Without the buff the multiplier is not equal to one, but × 1,5: The skill's default base chance is increased by 1.5 times. It only reaches 1 at 30—meaning that the second level of Mental Shield merely returns you to the "fair" chance.

Second. Level 4 gives ×0,67 vs ×1,5 - debuffs pass 2,25 times less oftenAnd with passive Wisdom, the total goes up to 70, and the multiplier drops to 0,33x, meaning the effects happen four times less often.

Upper limit - 90On it, the multiplier becomes zero, and the effect doesn't take place at all: the game crashes immediately, without rolling the dice.

It's not the only one. The full chain looks like this, with each step applied to an already modified number:

MEN does participate in the calculation, but not the way they usually writeIt is not added to the resistance - it is a separate multiplier. 2 − √bonus, which is the second step and has nothing to do with Mental Shield.

And it's lightweight. The MEN bonus table is very flat: the difference between the weakest and strongest MEN character in the game is about a 12% chance.

Doesn't save from stun. Stun is classified as "shock" and is covered by a completely different stat. Neither Shield Stun, nor Hammer Crush, nor Thunder Storm, nor Stunning Shot fall under Mental Shield—their lists are often confused.

Does not prevent paralysis. Paralysis has its own symptom and its own resistance, and Mental Shield does not raise it.

Does not protect against poison, bleeding, or buff removal. All three are separate families.

Doesn't work against skills without a trait. If an effect doesn't have a flag set at all, the sixth multiplier simply isn't included in the calculation, and any resistance is ignored. This is how Aura Flash works, for example.

Does not provide complete immunity. Even the fourth level leaves a multiplier of 0,67 - on its own it doesn’t reach the zero mark.

All sources are different and cumulative: passive skills, set bonuses, and jewelry are separate from the buff. Mental Shield is the only one that covers all three families at once:

"Chance = base × (1 − resist ÷ 100)". There's no such formula in the game. The resistance is inside a fraction with a denominator of 60 and an offset of 90—that's why without the buff, the multiplier is 1.5 instead of 1.

"Fear has a base chance of 80%." Fear has it in his files 20Eighty - for Silence, Sleep and Curse of Doom.

"MEN gives +20 resistance." MEN is not measured in units of resistance at all; it is a separate multiplier and a different calculation step.

"The attacker's INT affects the chance." Directly, no, it's not included in the calculation. Indirectly, yes: INT increases magical attack, which is included in the third step of spells. This doesn't apply at all to physical and mental abilities like Shield Slam.

"Mental Shield covers stun and paralysis." It doesn't cover them; they are different families with different indicators.