In my Chronicles of Ceteri campaign I ran a “mini-game” that was basically a mash-up of rules from GURPS Technical Grappling and some ideas I had. Here they are for use by others.
Each round make a ST- or DX-based Climbing roll (whichever is better). Success means you roll your thrust damage for “climbing points” (CP). Add +1/die for Climbing at DX+1 or +2/die for Climbing at DX+2. (Do not add climbing modifiers to this roll.) Next, determine how many dice the climbing obstacle has and its skill level. Its “skill level” starts at 14 and adds negative modifiers (to increase total skill) and subtracts bonuses (to decrease total skill). Next, determine the amount of climbing points it gets on a successful roll by adding it’s climbing penalty x2 plus 14. Add a negative value and subtract a positive one. So scaling a tree (normally a +5 to your roll) gives a skill roll of 9 and does 1d-5 CP.
Each successful roll takes 1 minute and lets the climber expend any number of accumulated CP. Each 4 CP spent allows the climber to move the listed amount on p. B349. At least 1 CP must be retained or the climber falls. Combat time may be used instead, but the climber takes a -2 on his rolls and must spend double the CP to move the listed minimum.
Failure reduces this amount by 10. Critical failure means the climbing obstacle gets a free roll to decrease the climber’s CP. Critical success gives the climber a free roll to increase their CP.
The GM may opt to reduce a climber’s CP by an equal amount (with each 4 CP becoming 1 die) each turn instead of rolling to accumulate more. A climber’s CP cannot fall below zero. At this point he must make a Climbing roll vs. the climbing obstacles skill – failure means he falls. Success means he holds on for now and can attempt a new roll next turn with the usual results.
Climbers cannot have more CP than their Climbing skill at any one time. Obstacles are not restricted this way! To catch a falling comrade, reduce your CP by 4 and make a DX or unarmed skill roll. Add your encumbrance penalties to this roll. Success means you’ve caught your subject, but must make an immediate skill roll vs. the climbing obstacle. Reduce your CP inflicted by half if using one hand or by 3/4 if relying on a rope or similiar device.
Example: Climbing a modern building in the normal rules inflicts a -3 to rolls and gives you 2 ft./minute when climbing (or 1 ft/10 seconds in combat time). Using these rules, its skill level to inflict CP becomes 17 and it inflicts 2d-1 CP. Assuming a climber has skill 16 and inflicts 1d+2 CP per turn he could just barely make 2 ft./minute per turn spent climbing.
Example 2: Climbing a tree gives +5 to rolls and and lets you scale 1 ft per 3 seconds. Using these rules, it would have its skill level would be 9 (14 – 5) and inflict 1d-5 CP per climbing attempt.
Example 3: Doug the Technically Correct (the best kind of correct) has a ST of 14 and a ST-Based Climbing of 16. He inflicts 1d+2 CP per climbing attempt. He’s trying to scale a stone wall to help Lady Asskicker assault the goblin fortress. Since a vertical stone wall is normally a -3 to climb it would start with a skill of 14 + 3 = 17. It would inflict 2d-1 since 14 +3(2) = ST 20 and ST 20 would inflict 2d-1 CP. The first round of climbing Doug rolls a 14 on his climbing roll and scores 8 CP. The GM rolls for the wall and fails inflicting a mere 1 CP. Since his total this round is positive he climbs 4 ft in one minute. Next round that could change!
Picking Over the Bones
This simple rules switch added a lot of flavor to my campaign when I used it. It made the very act of climbing dramatic instead of “Did I climb? Yes/No.”