XP Potions are potions that give you experience points but nothing else in Fable II. They occasionally turn up in dig spots, dive spots and chests and can be purchased from potion traders when available. Potion in Motion in Bowerstone Market stocks the 1 and 2 star potions occasionally near the beginning of the game, and as the economy of the area improves, the higher rated potions become available. For example, when Bowerstone Market has a 4-star economy, it will start selling 4-star goods, 5-star economy 5-star goods, etc. 5-star goods can usually be found in Fairfax Gardens from the travelling traders there. Quite a few 5-star goods spawn in the Fairfax Castle bookshelves in the tower-bedroom on the right.