During combat, players have the ability to equip both defensive and offensive fighters with potions. These potions are (with a few exceptions) one-time use items that increase a certain stat for the fighter.
Unlike the original Asterix comics, potions are never used in the fight against the Romans. Instead, brawl potions will occasionally drop when winning an attack against the Romans.
Battle Potions come in four types: Small, Medium, Large, and Incredible.
A complete list can be found in the Potions section.