The catch formula

TapIn Pokémon uses the Gold and Silver catch formula. It turns four things into one number from 1 to 255: the species' catch rate, the ball, the target's HP and its status.

Step by stepCopy Anchor Link

1. Start from the catch rate on the species' Pokédex page, from 3 (Mewtwo, Lugia, Ho-Oh) to 255 (Caterpie, Rattata, Sentret).

2. Apply the ball. Great Ball ×1.5, Ultra Ball ×2. Kurt's balls apply their own rule (Level Ball compares levels, Heavy Ball adds or subtracts by weight, and so on). The result is capped at 255. A Master Ball skips everything and catches.

3. Factor in HP:

a = floor( (3 × MaxHP − 2 × HP) × rate / (3 × MaxHP) )

At full HP this is a third of the rate; at 1 HP it is almost the whole rate. a is at least 1.

4. Add the status bonus: +10 if the target is asleep or frozen, +5 if it is paralyzed, burned or poisoned. The total is capped at 255.

5. Roll. The game draws a number from 0 to 255. If it is less than or equal to a, the Pokémon is caught. So the chance is:

chance = (a + 1) / 256

The number of shakes shows how close it was: the higher a, the more the ball shakes before it breaks.

Worked exampleCopy Anchor Link

A wild Pikachu (catch rate 190) is asleep with a third of its HP left, and you throw an Ultra Ball.

The same Pikachu at full HP, awake, in a Poké Ball: rate 190, a = floor(190 ÷ 3) = 63, chance 64 ÷ 256 = 25%.

Rules of thumbCopy Anchor Link

"Low HP" in this table is 1 HP. A Master Ball is the only sure way to catch a legendary Pokémon.