I literally have a headache from trying to work out how damage from convection (from lava) will work in my game. I've gotten what appears to be a reasonable, in game terms (that is to say likely not realistic in the slightest), formula for how far the heat can spread thru air and how it interacts with solid barriers (the spread is halved for each meter of solid barrier between the lava and the next available air block), but I'm having a bitch of a time figuring out how to say, in mathematical terms, "you'll take X damage per second per meter away from the lava you're near, depending on how hot the lava is and how far its heat can spread." Breaking things down to numbers is fun, but it can be a bear, lemme tell ya.
D&D generally uses 1d6 damage if you're in close proximity to lava, and 20d6 if you're actually in it. A good idea might be to increase the type of die used depending on distance (use 1d12 if you're within 5 feet, 1d4 if you're on the other side of the room, etc.)
I'm not using dice, though. Its not like a tabletop game I'm doing, but one of them thar evil vidya games. Besides, "feet?" I'll have you know my game uses metric units! Mostly because, when I go into doing the minimap, I want there to be distance displayed between you and your waypoints, in the best units for the job. So, if you're more than 1,000 meters away, it'll display using kilometers instead. Doing that with feet, yards, miles, and all that other garbage would be yet another bleedin mathematical headache. Not ragging on ya, of course, just mildly irritated how most games seem to default to Imperial units.
Also, the Imperial system itself bugs the fuck out of me. It is, as far as I've been able to learn, a load of arbitrary, retarded bullshit. The conversions between different units, in the same system, are so completely ass-backwards that its a miracle we were able to measure anything before the metric system became the accepted standard. Metric goes in simple orders of magnitude and is based off something easily quantifiable and measurable: water. 1 cubic meter of water is equal, in volume, to 1 kiloliter. One liter of water weighs (more or less) one kilogram. Water freezes at 0C and boils at 100C. Simple, clean, efficient, and easy to understand.