Mortar and Pestle is used for brewing potions.
Legend of GrimrockEdit
In Legend of Grimrock, the item acts as a container. Using it opens a small window with six slots that items can be placed in. If an empty Flask is placed in one of the slots along with mixable ingredients, the resulting potion will appear in the seventh slot. The Mortar and Pestle can be used by characters of any class.
Legend of Grimrock 2Edit
The mechanics of the Mortar and Pestle are dramatically revamped in the sequel. The item must be equipped by a character to be used; when activated, rather than slots for ingredients, a grid of the user's available ingredients will appear. Clicking on one will add one sample of it to the row at the bottom. If the ingredients selected will produce a potion, it will appear in the window on the right. Not only can potions be made, but the elemental bombs can be created by mixing one of the common ingredients with Blackmoss. Characters of any class can use the Mortar and Pestle, but they must devote at least one Skill Point to the Alchemy tree to do so. More potions can be brewed as more points are invested.