Flint is a natural resource found randomly in the island and is very important for the player's survival. Flint is one of the two things needed to make a fire. Using flint on dry leaves or dry grass (click and drag until a button appears saying "Set Fire" and let go) will make a fire. You can then add driftwood, planks or other kinds of objects that burn to make the fire bigger. Be carefull when looking for it, because you might mistake it for a rock.
>>>Also see Campfire<<<