What happens if a move’s accuracy somehow goes over 100%?

Question

So I’ve been browsing Reddit, and on r/Fakemon, I came across a Pokémon named Albatrice. The creator said it was made from the thought of a Pokémon with Sniper that gets STAB from Frost Breath. I was thinking of a way to make it extremely powerful, and I did some calculations that made it 100% accurate. I tried giving it a Zoom Lens, and the accuracy would’ve been 108. So, what would happen? Would it become unmissable? Would it just be 100% accurate?

Thanks in advance!

Answer 1

Nothing special really, it would just be guaranteed to hit. Accuracy in Pokemon and rpgs in general work like this: There is a value that is formulated which we will call "A" then the game will generate a random number from 1 to 100 (in gen I-II its 255) which we will call R. According to Bulbapedia, if R is less than or more than A, then it hits.

So R = 20 and A = 80? It hits. R = 75 and A = 80? It hits. R = 81 and A = 80? Doesn't hit.

In your example, A would be 108. Since R can only range from 1-100, it is guaranteed to hit every time.

Source: https://bulbapedia.bulbagarden.net/wiki/Accuracy
Also there's some cool info about how A is calculated in the games in this source, in case you're interested.

Answer 2

The only benefit you get from driving accuracy over 100% is that you have more of a cushion in case the opponent goes on to reduce that accuracy with evasion boosts or Bright Powder, so those effects won't impact you as much as they normally would.