Jump
A jump speed allows you to make extraordinary leaps as part of your movement. A jump speed of X means you can jump X squares horizontally or X/2 squares vertically (round down) as a move action. You can split a jump across horizontal and vertical distance (e.g. jump 6 could be 4 horizontal and 1 vertical).
Jumping does not provoke opportunity attacks for the squares you pass over — only for the square you leave and the square you land in, as normal movement. You must have a clear path through the air for the arc of your jump.
If you jump to a height greater than your remaining vertical distance, you fall from the apex. If you jump horizontally and there is no solid surface to land on at the end, you fall from whatever point you left solid ground.
A jump speed replaces the normal jump rules (which use Athletics checks and are limited by your walk speed). If you have both a walk speed and a jump speed, you can use part of your move action to walk and part to jump, splitting the distance between them.
Landing from a jump does not cause falling damage — the jump speed accounts for safe landing. However, if you are knocked out of the air mid-jump (e.g. by a reaction attack), you fall from that point and take falling damage as normal.