White Phosphorus Grenade

This dubious device inflicts terrible burns on those unfortunate enough to be hit by it. Use a hit roll to throw the grenade at a target. Add your strength mod to the roll.   On a hit, the target will take 5D10 fire damage and must make a DC 17 constitution saving throw or be set on fire. On a critical the target will take 10D10 fire damage. On a failed save the target will burn for 1D6 turns and take 1D12 fire damage per turn. Any creature within the blast radius will take 2D10 fire damage. A creature who is on fire fro more than 3 turns from a white phosphorus grenade will have their armor melt off due to the intense heat.   The phosphorus will burn for 6 turns if lands on the ground or a non living surface. Each creature that goes within 5 feet of it must take 2D10 fire damage.   This weapon can start uncontrollable fires if near flamable substances, or fill a room with toxic smoke if used in an enclosed area. If used in a a closed space, all creatures in the room take 1d10 poison damage. Use with caution.