The Exp. Share is an item.
Effects
When held by a Pokémon, it will give the Pokemon experience points in battle (even if the Pokémon holding it doesn't battle) after a foe's Pokémon has fainted.
Notes:
- The Pokémon holding the item needs to be in a trainer's party for this item to work.
- Multiple Pokémon can hold one in your party, but the experience is divided into more parts.
- When held by a Pokémon (excluding the exploitation scenario listed below) it splits the experience fifty-fifty.
Exploitation
If the player attaches an Exp. Share to the first Pokémon in their party, the Exp. Share is able to be manipulated to give more experience than it would if attached to any other Pokémon in the party. The process is simple; the player sends his/her first Pokémon (the one that is holding the item) into battle, and switches out immediately to another Pokémon. The player then has this Pokémon defeat the foe. Using this strategy, the Pokémon holding the Exp. Share gains 75% of the experience gained by both Pokémon in the battle, rather than the typical 25%.
Note: If the player's first Pokémon is holding Exp. Share, does not switch out, and defeats the opposing Pokémon on its own, the amount of experience that is gained is the same as if it were not holding an Exp. Share.