The traditional way of implementing climbing up stuff had been to use the climb trap. This has the disadvantage that it is haphazard, and doesn't trigger movement traps, or cause following to happen.

This can be fixed by using the new generic ladder objects. Set 'climbto' on the ladder to the location where the ladder leads, and then 'dir' to 'up', 'down', or whatever.

Then, whenever anyone climbs the ladder, they will trigger all the usual traps.