I know this is a bit of a stretch, but I’m going with it. Fire’s a fun thing in an RPG. At least, in some RPGs it’s fun.
I have an index card which was used in Fate Core. It said, “On Fire”. I used white index cards for Aspects and orange index cards torn in half for Boosts (one-off Aspects). These were narrative parts of the game which could be weaponised by players and NPCs alike for a bonus. You could use, “Sand in yer eyes” to temporarily blind a person and get a +2 to your roll. Environmental Aspects were more like, “Heavy Winds” which anyone could use, often with a free use or two. Players could use moves to add or remove Aspects.
So then we have “On Fire” and why any of this is important. I liked piling up the Aspects and Boosts at the end of a session as it created a weird collage of words. There was one which happened multiple times during a game of Spirit of the Century. I ended up realising that I needed to keep only one Aspect card between sessions. “On Fire.” No matter what, the group ended up burning things. It’s a nice Aspect for hindering people, but also for using in fights or dramatic scenes. Folks were able to set light to weapons when fighting someone or having bits of scenery fall down on an NPC.
The John Wick (not that one) games use fire as a good tool against the players as options for Risks in Houses of the Blooded and 7th Sea Second Edition. As an example you have the initial challenge, “Get through the burning room” and add risks like, “You get burnt” or “You lose something in the fire.” You can even have opportunities like, “You find evidence of who set the fire.”
Finally, I have a cautionary tale about fire, from an RPG I still have a lot of fondness for. Fantasy Craft. The player-facing side is mostly great, even for a d20 system game. It had backgrounds before 5E and did more interesting things with them. It had so many great actions which could be done in combat without you having to be great at fighting. We had an actual pacifist priest in ours who would tire or stress out foes. Most of the problems were with the GM-facing side such as the weird need to have scaling foes complicating any enemy creation. The biggest exception to this player side good, GM side bad structure was fire. Fire was not fun for anyone. Fire was incredibly infectious and fiddly.
One of my group, Steve, decided to run Pathfinder’s Rise of the Rune Lords using Fantasy Craft. A noble idea, especially as it meant I didn’t have to play Pathfinder, but for a first GMing attempt I’d have recommended something requiring less work. One of the group, Josh, decided he’s play a priest type character and pay all of his money into a donation box with the expectation the plot would provide something interesting. Again, a nice idea, maybe less so with a new GM. So he got a stick when we went into a dungeon, didn’t have any armour and promptly went on fire when facing a monster. Everyone had played a couple of seasons of Fantasy Craft with me at the helm, so they knew I had a literal print out of the fire rules handy just in case I had to deal with them. I also had Alex, a player who actually engaged with crunchy rules more than I did and was willing to be my bookkeeper when it came to fire. So Josh’s priest was on fire, and everyone saw the rules sheet come out. We all stood back. He wasn’t able to put himself out and we weren’t willing to help him as fire spreads like you’re covered in petrol in Fantasy Craft. We all stood there for a few rounds, watching our priest burn to death from damage which armour he could have bought would have soaked before it hit his surprisingly flammable flesh.
Maybe ‘rare’ was the wrong word for that anecdote?