Alchemist Fire

You can throw the flask up to 20 ft. replacing one of your attacks on your turn. It explodes in a 10 ft. cube. All creatures in the area take 2d4 fire damage at the start of each of their turns. They can use an action on their turn to make a DC 10 Dexterity check to extinguish the flames. All nonmagical objects that aren´t worn or carried are set on fire.