Learned about something interesting today. Now, the information was news to me, either because I forgot elementary level or high school chemistry or because it wasn't part of the curriculum, as the education system is generally a mess. Turns out, that if pretty much any sort of acid starts eating away at something, say, aluminium or someone's face, the gas it produces from all the foaming and stuff is highly explosive. Flick a lit match at it or fire a flare into it and if the concentration is high enough, you're off to the races, whether you like it or not, with your limbs not necessarily still attached, I imagine. Now, this is interesting, because we're used to certain elemental combos or just using a certain element against something that may be more vulnerable to it, in games. I don't think I recall ever seeing an acid + fire = explosion combo. Combustion, maybe. But, definitely not explosion. It could be an interesting mechanic, when fighting just about anything, really. If it's something inorganic/mechanical, then, acidic/chemical/corrosive weapons could eat away at it and when enough of a gas cloud surrounds it, a flare or some other high heat-source could cause an explosion, sending parts of it or its armor, outer shell...etc. flying off. When it's some fleshy thing is bathed in acid (creates a methane cloud or something) it can be set off in a similar fashion. And if neither target dies outright, they'll take a huge hit and could even be dazed from the concussive force of the explosion, if they aren't already in pieces.