Pokémon Ruby Version, Sapphire Version, and Emerald Version - Exp. Points
Whenever a Pokémon on the opposite side of the player faints in a battle against a wild Pokémon or an in-game Trainer, each Pokémon that participated in the battle against it gains Exp. Points (or experience points). The number of Exp. Points a Pokémon gains this way is based on a formula shown below. Each multiplication and division given is rounded down.
Formula used if no unfainted Pokémon controlled by the player is holding an Exp. Share:
Exp. Points = (max(1,(L*G/7)/E))*X*Y*Z
Formula used if at least one unfainted Pokémon controlled by the player is holding an Exp. Share:
Exp. Points = (max(1,int(M/E))*A+max(1,(M/F))*B)*X*Y*Z
where:
- L = Defeated Pokémon’s level
- G = Base Experience for the defeated Pokémon’s current species
- X = If the battle is a Trainer battle, X=1.5; else 1.
- Y = If the participating Pokémon’s 32-bit Trainer ID, OT name, or both are different from the player’s, Y=1.5; else 1 ("[name] gained a boosted [value] Exp. Points!")
- Z = If the participating Pokémon is holding a Lucky Egg, Z=1.5; else 1.
- M = ((L*G/7)/2)
- E = Number of unfainted Pokémon that participated in the battle against the defeated Pokémon
- F = Number of unfainted Pokémon that are holding an Exp. Share
- A = If the Pokémon participated in the battle against the defeated Pokémon, A=1; else 0.
- B = If the Pokémon is holding an Exp. Share, B=1; else 0.
A "participant" means each unfainted Pokémon (other than an Egg) that is controlled by the player and that had seen the opposing Pokémon since the last time the opposing Pokémon entered the battle. A participant need not have used an attack against the Pokémon, but must merely have seen it. If a Pokémon faints at the same time as the opposing Pokémon, it doesn’t count as a participant. (In battles in which Exp. Points can be gained, if both sides have no Pokémon at the same time, it is considered a loss for the player.)
When a Pokémon gains a level, its current HP is its new HP minus the HP lost before the level gain. A Pokémon gains levels one at a time, in case it earns so much experience at once that it gains more than one level.
While a Pokémon is in the Day-Care, it will earn 1 Exp. Point for each step the player walks and will learn new moves as it gains levels; such moves, if the list is full, will overwrite older moves, starting from the top of the list. (Even HM moves will be overwritten this way.)