Spotting rivers

[Shinoskay]

A few of my players have started exploration.

I feel like spotting rivers and such is pretty simple and obvious, - level perception stuff.

Does kingdom builder or anything else have rules for finding rivers or other such features?

[Meirril]

I think it is fairly self explanatory.

Exploration and Movement Rules

Once you get enough discovery points you should know about every major feature in an explored area. Rivers are considered major features though minor streams and creeks might not be in areas where water is easily obtainable. Likewise a shallow pool would be considered a major feature in a desert area.

[Shinoskay]

What about spotting a river while flying over head? basically, what can be easily assumed to be seen

[Meirril]

That is up to the GM. There is no perception check to spot landmarks because landmarks are suppose to be obvious. If the GM feels something is hidden, then it is hidden. If the GM doesn't have a reason to hide something, it should be just stated without a perception check.

If you try to follow the rules for perception, PCs can't see the moon. The distance is just too great, the negatives would bury you. Only use perception checks when it makes sense to do so.

[Quixote]

If you're looking for regular-ol' PC exploration, The Angry GM has a pretty great article on it. I use an adaptation of that for all of my travel-based stuff.