Q: Doesn't additional Precision give Crit Damage when stacked?

Yes. Each Precision source after the first grants +10% Critical Strike Damage. The current item texts say each additional source grants 10% Critical Strike Damage. It is not Damage Amp, so it adds nothing to hits that do not crit. It raises attack crits, and ability crits once the unit has Precision. The unlock half of the keyword is the same: the first source lets abilities crit. Only the extra sources add Crit Damage. Note: Some older guides say the stacking reward is Damage Amp. The current item texts say Critical Strike Damage.

Q: Do multiple Precision sources stack additively or multiplicatively?

Most likely additively. Each extra source adds +10% to the unit's Crit Damage stat. One source unlocks ability crits and adds no Crit Damage. Two sources add +10% Crit Damage. Three sources add +20% Crit Damage. The item texts only say 'Additional Precision grants 10% Critical Strike Damage.' They do not spell out the math. Crit Damage is a flat stat, though, and flat stat bonuses add together. Note: The unit's stat panel on a live board shows the running Crit Damage total. It is the cleanest way to check.

Q: If a trait already gives my unit Precision, is stacking Precision items still worth it?

Partly. Each extra Precision item adds only +10% Crit Damage from the keyword. The trait's Precision already claims the 'abilities can crit' unlock once per unit. Every extra Precision source on top of that adds +10% Crit Damage. That bonus only pays off on hits that crit. So most of a second Precision item's value is its own stats, not the keyword. Note: The Crit Chance and AP/AD (Ability Power and Attack Damage ) stats those items also carry are independent of the keyword. They still scale the rest of the unit normally.

Question 1

What is Precision in TFT?

Accepted Answer

Precision is a keyword on items, traits, and augments. It lets ability damage critically strike.

The keyword text reads: 'Precision: Ability damage can critically strike. Additional Precision grants 10% Critical Strike Damage.'

The first half is the long-standing rule. By default ability damage cannot crit. A Precision source flips that switch for the unit holding it.

The second half is the stacking reward. Every additional Precision source after the first hands the unit +10% Critical Strike Damage.

Question 2

Doesn't additional Precision give Crit Damage when stacked?

Accepted Answer

Yes. Each Precision source after the first grants +10% Critical Strike Damage.

The current item texts say each additional source grants 10% Critical Strike Damage.
It is not Damage Amp, so it adds nothing to hits that do not crit.
It raises attack crits, and ability crits once the unit has Precision.

The unlock half of the keyword is the same: the first source lets abilities crit. Only the extra sources add Crit Damage.

Note: Some older guides say the stacking reward is Damage Amp. The current item texts say Critical Strike Damage.

Question 3

Does the extra Crit Damage from stacked Precision help basic attacks too?

Accepted Answer

Yes. It is a plain Crit Damage bonus, so it raises every crit the unit lands.

Basic attacks that crit deal more damage.
Ability hits that crit deal more damage too, since the unit has Precision.

It does nothing on hits that do not crit. So it pays off most on a unit with high Crit Chance.

Note: This bonus is not Damage Amp. It does not raise every hit the unit deals.

Question 4

Do multiple Precision sources stack additively or multiplicatively?

Accepted Answer

Most likely additively. Each extra source adds +10% to the unit's Crit Damage stat.

One source unlocks ability crits and adds no Crit Damage.
Two sources add +10% Crit Damage.
Three sources add +20% Crit Damage.

The item texts only say 'Additional Precision grants 10% Critical Strike Damage.' They do not spell out the math. Crit Damage is a flat stat, though, and flat stat bonuses add together.

Note: The unit's stat panel on a live board shows the running Crit Damage total. It is the cleanest way to check.

Question 5

If a trait already gives my unit Precision, is stacking Precision items still worth it?

Accepted Answer

Partly. Each extra Precision item adds only +10% Crit Damage from the keyword.

The trait's Precision already claims the 'abilities can crit' unlock once per unit.
Every extra Precision source on top of that adds +10% Crit Damage.
That bonus only pays off on hits that crit.

So most of a second Precision item's value is its own stats, not the keyword.

Note: The Crit Chance and AP/AD (Ability Power and Attack Damage) stats those items also carry are independent of the keyword. They still scale the rest of the unit normally.

Question 6

If I stack Crit Chance on an ability carry without any Precision source, does my Crit Chance still do anything?

Accepted Answer

Yes, for basic attacks. It still applies to that unit's basic attacks between casts, but it does not affect ability damage.

The TFT wiki rule still holds: 'most abilities are unable to critically strike on their own'.
That is exactly what the first half of the Precision keyword unlocks.
Without a Precision source on the unit, ability damage ignores Crit Chance and Crit Damage entirely, no matter how high they go.

Note: For an ability-heavy carry that means raw crit stats are mostly wasted until you slot in at least one Precision source.

Question 7

Does Precision change the damage type of an ability, or how the spell calculates its base damage?

Accepted Answer

No. The unlock half of Precision only changes whether an ability hit is allowed to roll a critical strike.

It does not touch the damage type.
It does not touch the scaling source.
It does not touch how base damage is computed.

A magic-damage ability with Precision still deals magic damage and still scales from Ability Power. It just lands as a critical strike when the Crit Chance roll succeeds.

The stacking half is +10% Crit Damage per extra source. It only matters on hits that crit.

Question 8

How does Precision interact with the rule that Crit Chance above 100% converts into Crit Damage?

Accepted Answer

It compounds cleanly. Precision does not change the conversion itself.

The conversion rule is on the Crit Chance side. It reads: 'critical strike chance cannot be increased beyond 100% but increases critical damage to an amount equivalent to the excess.'

Precision's first source decides whether the resulting Crit Chance and Crit Damage values get to apply to abilities at all.

Example: A Precision-active unit at 120% raw Crit Chance ends up at the 100% cap. The extra 20% is folded into Crit Damage. That Crit Damage figure now multiplies ability hits as well as basic attacks.

Note: Additional Precision sources add +10% Crit Damage each. That stacks on top of any Crit Damage gained from Crit Chance above 100%.

Precision

What enables Precision (9)

Champions that grant Precision (1)

Traits that grant Precision (1)

Completed items that grant Precision (2)

Radiant items that grant Precision (2)

Augments that grant Precision (3)

Prismatic (2)

Gold (1)

What scales with Precision (2)

Champions that scale with Precision (1)

Wisps that scale with Precision (1)

See also

Frequently asked questions

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