Fire and explosives can permanently change a place, so they carry more coordination than most actions. The rules scale with the damage: a small flame is nearly free to play, while anything that could scar a building brings other people into the planning. This keeps destructive scenes dramatic and fair rather than unilateral.
Fires at buildings need consent
Setting fire to a business, home, or other building requires the consent of that property’s owner. A large fire that could cause structural damage also needs admin approval, and coordinating with the Fire Department is required, because the Fire Department trains for dramatic rescue scenes and deserves the chance to run one. They handle setting and extinguishing the blaze, and if a building is damaged they can board it up for a couple of days, no longer.
Small fires are yours to play
A small fire that would not cause significant damage needs no admin or Fire Department approval. As a courtesy, still try to notify the Fire Department in case they are available and want in; if none are online, an admin can help set the scene. If you are reaching for something bigger, plan ahead and let the Fire Department be part of the story rather than springing it on them.
Explosives and molotovs
Using explosives always requires admin approval, without exception. Molotov cocktails are allowed as long as it is plausible your character had the components on hand or brought them; carrying several ready-made firebombs around without a good reason strains belief. Whatever the source of the flame, the same damage rules as any other fire apply.
Keep destruction collaborative and the worlds stay standing for everyone’s stories. Next, the rules for playing a non-human character.