Pokémon Ruby Version, Sapphire Version, and Emerald Version - Catch Rate Formula
This formula determines whether catching a wild Pokémon or Snagging a Shadow Pokémon will be successful.
X = (((A*3-B*2)*C)/(A*3))*D
where:
- A = opposing Pokémon’s maximum HP
- B = opposing Pokémon’s current HP
- C = catch rate, initially equal to the starting catch rate value for the opposing Pokémon’s current species
- D = opposing Pokémon’s status: if asleep or frozen, D=2; if burned, paralyzed, or poisoned, D=1.5; else D=1
If X is 255 or greater, capture succeeds. If X is 0 or less, it becomes 1.
Y = 1048560 / (sqrt(sqrt( 16711680/X ) ) )
"sqrt(N)" means "the square root of N." To find the square root of a number, set M and P to that number. Then calculate (M+P/M)/2, rounding each division down. If M equals or is less than the result, use M as the square root; otherwise, set M to the result and repeat this process at the calculation step.
Four random numbers from 0 through 65535 are then generated. If all of them are less than Y, capture is successful. Otherwise the number of times the ball shakes before it breaks is equal to the number of random numbers less than Y.
Balls
Different Balls have different rates of success. Below are the multipliers to the catch rate for each Ball.
- Poké Ball - multiplier is 1.0
- Great Ball, Safari Ball - multiplier is 1.5
- Ultra Ball - multiplier is 2.0
- Master Ball - no formula is used, capture succeeds automatically
- Net Ball - multiplier is 3.0 if opposing Pokémon’s type includes Bug or Water; else 1.0
- Nest Ball - if the opposing Pokémon’s level is at least 30, multiplier is 1.0; else multiplier is (40-(opposing Pokémon’s level))/10 (not rounded).
- Dive Ball - multiplier is 3.5 if underwater; else 1.0
- Repeat Ball - multiplier is 3.0 if opposing Pokémon’s current species was caught before; else 1.0
- Timer Ball - multiplier starts at 1.0 and rises by 0.1 for each turn completed in the battle, but not to more than 4.0.
- Premier Ball - multiplier is 1.0
- Luxury Ball - multiplier is 1.0
A wild Pokémon or Shadow Pokémon can be caught with a Ball even if it’s currently using Dig, Fly, Dive or Bounce; if the capture fails, that doesn’t affect that Pokémon’s two-turn attack. In Double Battles, a wild Pokémon or Shadow Pokémon can be caught even if there is another Pokémon on the same side as that Pokémon.