Exp. Share is an item in the “Training” category (Items).
In-game descriptions
| Ruby / Sapphire · Emerald | A hold item that gets EXP. points from battles. |
|---|---|
| FireRed / LeafGreen | An item to be held by a POKéMON. The holder gets a share of EXP. points without having to battle. |
| Diamond / Pearl · Platinum · HeartGold / SoulSilver · Black / White · Black 2 / White 2 | An item to be held by a Pokémon. The holder gets a share of a battle’s Exp. Points without battling. |
| X / Y · Sun / Moon · Ultra Sun / Ultra Moon · Let’s Go, Pikachu! / Let’s Go, Eevee! · Sword / Shield | Turning on this special device will allow all the Pokémon on your team to receive Exp. Points from battles. |
Where to find it
Not placed on the atlas maps (so far: Red/Blue and Generation 3).
Sources : PokeAPI (items, item_flavor_text, machines) · atlas · pokeemerald species_info.h