Obviously I don’t need to describe that. It would slow your units’ movement, and it would fight poorly in mud, while these hinderships (I made up that word) wouldn’t be as pronounced as in a forest. It would also slow down tunneling.
It could also slow construction and training time, depending on what it is.
That's something I'd like to have in the game too, except for the tunnels. It's... I dunno... unlikely that tunnels would be finished before a long time, as well as that the longer they get, the more likely it is to collapse at any time.
If it is raining and your troops are trying to climb dangerous mountain terrain, they could slip and fall, getting killed. Maybe not a practical, or really that great of an idea, but I thought it’d be funny. Besides, I don’t think random falling-off has ever been used in a game/RTS, and it’d surely affect someone if they’re trying to attack an enemy base. They’ll have to risk losing units, or call off/delay the assault.
:lol: That would be because it's pretty annoying to have your troops fall down and die because of rain

Things like that are just unlikely to happen, not often in any case. It could be something of an unique effect, but it would be something of an extra. It shouldn't be applied to any experienced/hero units either, as loosing a rookie would be considered fun for the effect, loosing a hero would only cause serious annoyance. "Why the bloody %#^& couldn't he watch his step!?! He killed hundreds in battle, but he dies because of a slippery slope!?!"
Solinx