Using this potion grants the user a base amount of Will experience. In Fable, it gives 100 Will experience points. In Fable: The Lost Chapters, this is increased to 1,000 (Equipping a weapon with an Experience Augmentation will increase this amount). This base amount is then multiplied by the player's current Combat Multiplier. For example, in Fable, drinking this potion with a combat multiplier of five would yield 500 Will experience points. In The Lost Chapters, this same combat multiplier would yield 5,000 Will experience. Therefore, it's best to use this potion after or during combat, and to try to attain the highest combat multiplier possible beforehand.