[M036462]

I'm designing a post-apocalyptic hexcrawl and have been reading up on all the various rules for travel and navigation, like After The End2, DF16: Wilderness Adventures as well as The Alexandrian's excellent commentary on d20 hexcrawls. One of the things I've noted is that GURPS Navigation rules seem to consciously omit penalties for terrain type, which strikes me as odd. My only personal experience with navigation is the (under)sea type so I wanted to get everyone's opinions here on the topic.

I would think that areas where it is difficult to find a follow a landmark would be more difficult to navigate in then others, so areas like dense forests and jungles should get a penalty, as well as areas like moorland where it is relatively featureless and the undulating terrain makes it more difficult to keep the landmark in view.

Part of the problem comes from what the consequences of a failed navigation check. ATE and DF16 treat navigation checks as giving a bonus or penalty to travel speed. Terrain type is already factored into travel speed and some of the modifier is undoubtedly due to navigation difficulty of the terrain, which leads to not adding an additional penalty to the check. I am planning on using a failed navigation check to send the party into the wrong hex which makes me lean toward including a terrain penalty for navigation.

So, should terrain have a penalty and if so, what magnitude for what terrain, or should navigation not be linked to the terrain type?