But do you take the available climbing movement (40 ft), or ground speed movement (100 ft, or 200 ft if running)?

I would argue that you use the movement speed of the movement mode you are employing. Because anything else seems silly to me.

The persistent underlying assumption of the standard rules seems to be that characters have only a land speed, and thus that they will only be using their land speed, so the issue isn't really addressed in the RAW directly.

No huge house rule is needed, in my opinion.
The spider climb spell specifically states it gives you a climb speed. So now you get +8 to your check, and can take 10 if you need to. Assuming you maybe put 1 rank in there, have like +6 STR or so, that is a climb check of DC 25 without evey really trying.

Those rules mean your land speed, not your climb speed. If they meant your climb speed, people without a climb speed couldn't climb at all.



If you ask me, treat it in portions as exactly what it is:
First: pushing off the ledges on the wall. This one's the tricky bit. I would eyeball it at making a climb check of the wall's DC: it's what you need not to fall off when hacking into the wall while hanging on it, or putting pitons into it. Maybe a +2 or +4.
Second: the jump. Standard High Jump, no funny business.
Third: now you're airborne, and you need to hang on to a wall. This looks a job for... "catch yourself while falling" because you're basically doing the same thing: grabbing onto a wall while flying past it.

I never said that it only applied to climb speed. At least I don't think I did... His half-ogre has a land speed of 50'. So he can climb at 50' per round by taking a -20 to his climb check.

That's interesting about the +8 on climb with a climb speed. I missed that. That would allow him to climb at 25 ft on most walls.

About the "catch yourself while falling": there are two additional factors: firstly, at the top of a high jump, he is effectively hanging still, which should make it easier. Secondly, he can climb on nearly any surface, so it might be enough to just stick out his hands against the wall. There are also no additional acceleration forces at his highest point. Ideally, he'll catch himself slightly before that moment, so he can use the upward momentum to continue climbing.

Now, suppose he is climbing a wall with a DC of 25 or less, so he can just take 10 and move at half speed of 25 ft (jump bonus is +12). Would this be reasonable: jump 5 ft up (DC=20x2=40 because he didn't move 20 ft, with a jump check of +30, he can take 10) at land speed of 50 ft, pull himself up 5 ft while climbing at 25 ft, and repeat. This would result in a speed of 37.5 ft, or 75 ft in a full round.

EDIT: on closer reading, double climb speed with a climb speed is only -5, not the -20 of the epic rapid climbing. So he could climb at a speed of 40 ft without even jumping, or am I missing something?

That's what the +8 to climb is for.

A reasonable point. Perhaps a DC 15 Reflex, like you use when you barely fail a Jump check and grab on to the ledge, is a better option?