In my campaign, there is a crazy old shopkeeper NPC who has some arcane knowledge. In preparation to defend the town against an incoming zombie horde, the party paid him to make twenty one-pound small explosive barrels. Eighteen of those barrels were used to set a trap, and the party kept two. One of my players just decided to lob one into an oil fire in front of some charging enemies, and it happened to be convenient to end the session at the apex of the arc.
I am looking for the most RAW-conformant answers to two questions, considering the balance implications of having the primary effect (explosion) triggering a secondary effect (oil):
- How do I model the damage from the explosive? I want to treat this as thunder damage.
- How do I model the damage from the fire, both from entry into the hazard and from splashed flaming oil?