The Protectors of Etheria is a stand-alone mod of the game Warlords Battlecry 3 (i.e. it can be run without having the original game installed - 100% free full game). It is an improved RTS/RPG game with new campaigns, quests, terrain, units, items, heroes, modding features and more. Beta versions available for download!
Tiles and buildings updates in 0.88
Small Lava pools, that looks nice. Do they damage infantry passing through?
Units don't pass through lava even if your order them to. They're not suicidal (well, most of them anyway).
But what about floating units?
Floating units aren't suicidal enough to float above lava either, since they only float a small distance from the surface beneath them.
Flying units can fly above lava but even at their height the uncomfortable heat does affect them - no damage though, but their resistance takes a hit, making them more vulnerable to elemental attacks and illnesses. There are a few units that can tolerate the heat - Dragons are some of them.
So Lava does have effects.
A shame that Fire Elementals cannot float over it, though it kind of makes sense, because at that temperature, they might not have enough oxygen to keep burning.
Fire Elementals DID float over lava and back during the development of 0.8.7. But due to a serious bug which proved too tricky to resolve within the time we allowed ourselves before release, the change was undone instead of delaying the release any further.
It may be revisited for 0.8.8, but we already know the hurdle that will come with it so it's not a priority, especially since it's such a small gain.
P.S: Salamanders were made to move over lava as well.