Failure and GP costs
I've confirmed the GP cost effects of failing to climb. Note that this isn't exactly what is in the mudlib - the mudlib has the GP cost as a random number between 0 and twice the original GP cost; whereas I've seen a range of values which are always less than one times the original cost. Specifically, for a 62 GP climb, I've seen the following additional GP costs incurred from failing: 52, 61, 41, 54, 61. Note that this doesn't seem to be a particularly flat distribution - all the values are at the high end of the scale - so I suggest more research is required to determine whether the scale actually goes all the way down to 0x the original cost or not.
According to the mudlib, the GP cost of a successful climb is half the difficulty - but I can relatively frequently fail climbs with GP cost 62 and bonus over 4x that (which ought to give 99% chance of success). Therefore, something has probably changed in this area - perhaps the successful GP cost is now 1/4 the difficulty? This would seem to fit better with the success rate I have.
For reference, my climbing bonus (rock) for the tests was 269, and 'climb <direction> assess' reports '62 GP' and 'fairly average'. The tests were performed on the wall by the mommet (Riverwind Walk) in Ohulan Cutash.
--Chat 22:47, 15 August 2009 (UTC)