#13 is a Tumble. If the runner makes a Tumble check of DC 25, for up to 20' of his movement he does not provoke AoO and can pass through enemy-occupied spaces. If he fails the check, he can still move through the ogre's square, but he'll draw an AoO (and probably get grappled).
Note, however, that he may suffer an AoO in any case. An ogre's threatened area is 25' straight across-- 10' reach in all directions, plus the 5' square he occupies in the middle. If the halfling must go across a diameter, he can't Tumble far enough to get past cleanly. His best shot is to start from a side and "caddy corner" through the threat area.
Note, however, that he may suffer an AoO in any case. An ogre's threatened area is 25' straight across-- 10' reach in all directions, plus the 5' square he occupies in the middle. If the halfling must go across a diameter, he can't Tumble far enough to get past cleanly. His best shot is to start from a side and "caddy corner" through the threat area.