The group that I play with, for a while now have been understanding the rules for difficult terrain such that you can take a 5 foot step into it but not out of it.
I just read the feat nimble moves though:
Benefit: Whenever you move, you may move through 5 feet of difficult terrain each round as if it were normal terrain. This feat allows you to take a 5-foot step into difficult terrain.
When talking about the 5 foot step the rules only mention that you can use it only when your movement is not hampered.
You can only take a 5-foot-step if your movement isn't hampered by difficult terrain or darkness. Any creature with a speed of 5 feet or less can't take a 5-foot step, since moving even 5 feet requires a move action for such a slow creature.
The rules for a 5 foot step in difficult terrain don't seem to cover what I am asking about
In some situations, your movement may be so hampered that you don't have sufficient speed even to move 5 feet (a single square). In such a case, you may spend a full-round action to move 5 feet (1 square) in any direction, even diagonally. Even though this looks like a 5-foot step, it's not, and thus it provokes attacks of opportunity normally.
Does this mean we have been using the 5 foot step and difficult terrain wrong or are the rules ambiguous?