[TFT] Does Frozen Heart Stack in Teamfight Tactics? (Patch 9.20)

(Oct 9 Update: In TFT Patch 9.20, Frozen Heart debuff duration has been reduced from 4 to 1 second.)

TFT Patch 9.15 came with some pretty disgusting bugs, and one of them was related to Frozen Heart (FH)  stacking its own debuff (again, we think it’s important to emphasize that the bug was about 1 Frozen Heart stacking its own debuff, which got immediately fixed).

In this article we’ll cover this topic and answer the question: “Does Frozen Heart Stack in TFT?“, withouth taking into consideration any bugs that will eventually get fixed anyway.

Does Frozen Heart Stack in Teamfight Tactics?

Yes, it does and this is how it’s intended to work. Riot Mort confirmed on Twitter that multiple Frozen Hearts are supposed to stack in TFT, but with a reduced effect. You can skip to this part where we explain the “reduced effect” part below with some numbers.

[TFT] Does Frozen Heart Stack in Teamfight Tactics?
[TFT] Does Frozen Heart Stack in Teamfight Tactics?
First of all, let’s see why there’s a lot of players complaining about Frozen Heart Pyke breaking the meta after the TFT Patch 9.15 update. The bug here was caused by the Frozen Heart debuff stacking itself when Pyke was around units that still have the debuff on them.

Here’s how the interaction worked: there’s a Pyke with one single Frozen Heart on him. At the start of the fight he jumps over the enemy team and Frozen Heart applies the debuff to all units that he jumps over (again, this is intended, not a bug). Then after filling his mana bar, he would jump back. If he crosses again a unit that’s still debuffed from his previous jump, that unit will be debuffed again, so it would have the Attack Speed reduced by another 25%, and this isn’t supposed to happen.

Ok, so now we know that it is supposed to stack, but this raises another big question:

Do 2 or 3 Frozen Hearts stack on the same champion?

Yes, they stack no matter how they are distributed on the units placed on the map. You should think of them as individual items who apply their own debuff and the debuff is the effect that’s actually stacking.

TFT Pyke Frozen Heart Stacking Patch 9.15
TFT Pyke Frozen Heart Stacking Patch 9.15

Let’s look at the 2 specific examples:

3 Frozen Hearts on the Same Champion

Let’s take Pyke for example, because this seems to be the current “meta”. We stack him with 3 Frozen Hearts. Whenever he jumps an enemy unit, that unit gets the Attack Speed slow debuff from all 3 Frozen Hearts, which lowers his Attack Speed to 42% (below we explain why it’s 42% and not 25% as some people expect).

3 Frozen Hearts on 3 Different Champions

Now in order for the Attack Speed slow to proc, each of these 3 champions have to be adjacent to that enemy unit while the other debuff is still active in order for them to stack.

How Frozen Heart Stacking Works: Some Numbers

So, now that we know that Frozen Heart does stack in TFT, let’s look at some numbers.

Most players misleadingly consider that the Frozen Heart Attack Speed slow simply adds up, so if one FH reduces the AS by 25%, it means 2 FH will reduce the AS by 50%, while 3 FH will reduce the AS by 75.

That’s totally wrong!!!

This is not how Frozen Heart debuff stacking works.

Here comes the “reduced effect” we mentioned in the beginning of this article. You need to understand that the 25% decrease in Attack Speed is calculated from the CURRENT Attack Speed, no the initial AS.

Here’s the actual formula to calculate the Attack Speed after the Stacked Frozen Heart debuff:

Final AS = Initial AS * (0.75^x) – here x is the number of Stacked Frozen Hearts.

No. of Frozen HeartsUnit's Attack Speed  
No FH100%
1 FH75%
2 FH56.25%
3 FH42.18%

Here’s how it works:

For simplicity of calculations in this example, we’ll consider Vayne with some Recurve Bows that has 1 Attack Speed.

  • If an enemy with 1 Frozen Heart is adjacent to her, her AS is slowed by 25%, which means now Vayne has 0.75 AS
  • If a second FH comes adjacent to her, her CURRENT AS will be lowered by 25%. Her current AS is 0.75, which means 25% of that is ~0.19, which means her AS will be lowered to 0.56
  • If a third FH comes adjacent to her, her CURRENT AS will again be lowered by 25%. 25% out of 0.56 is 0.14, which means the new AS will be 0.42

Hopefully this clarifies how Frozen Heart Stacking works in TFT after the 9.15 Patch. We’ll update this article if Riot decides to make any changes to this interaction.

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