[Rasputin]

Originally Posted by Kelly Pedersen

Low-Tech actually does have some guidelines for this, although they're more a matter of simply specifying that a rope automatically breaks once it exceeds its listed weight limit (which is halved for dynamic loads such as climbing or arresting a suddenly-dropped weight). See Low-Tech p. 23, "Rope, String, and Thread".

I looked at that before posting and no, they don’t say that the rope breaks. All they say is that rope won’t support more than the listed weights:

Originally Posted by GURPS Low-Tech, p. 23

The weights listed below assume stationary loads: hauling cargo, suspension bridges (see GURPS Low-Tech Companion 3), etc. For situations where the rope undergoes dynamic loads and sudden shock – e.g., towing and climbing – it can support only half as much. For instance, that rope with a maximum load of 281 lbs. will only support 140 lbs. if the user is climbing quickly . . . or if he falls and the rope must save him! If he climbs slowly (less than half normal climbing speed), the rope will support the full 281 lbs.

There’s nothing in there about actually breaking, though you could read that into it. You could also say that the rope slips or loses its catch, though admittedly to a climber it’s little different.

Originally Posted by Kelly Pedersen

If you want something more complex than "if the rope exceeds its maximum weight, it breaks", I'd suggest something like you proposed (a HT roll to avoid breakage), but starting a little earlier than max weight - for instance, have the rope roll HT starting at 50% of max weight, but with a +1 bonus for every 10% it's under max weight, and a -1 for every 10% it's over. For example, a silk rope has a max weight of 5000 lbs. under stationary load. Having it lift 2500 lbs. would force it to make an HT roll, but at +5. Subjecting it to a load of 5500 lbs., on the other hand, would force an HT roll at -1. For stationary loads, I'd only have the rope roll once, and if it succeeded, it would hold, at least until environmental conditions caused it to deteriorate. For dynamic loads, I'd have the rope roll once per hour of normal use, and every time it was clearly subject to a sudden shock. So, roll once an hour of climbing, for instance, and every time someone actually fell and a rope might arrest the fall.

Yeah, I was figuring something like that. That actually gives a nice starting point.

Originally Posted by Kelly Pedersen

I wouldn't have a critical failure of Climbing or similar skills automatically snap a rope, under this system. Instead, I'd suggest that a critical failure of skill would add (1dX10)% more weight to the most heavily-laden rope than planned, potentially requiring a check to see if it breaks.

I was proposing having Climbing critical failures snap the rope if the climber has already gone over the listed weight. Under that, the rope is still fine.

Originally Posted by Kelly Pedersen

Having a relevant skill at 15+ could justify a perk to avoid having to roll HT rolls for ropes whose effective HT scores, after modifiers, was 16 or higher, effectively a "No Nuisance Rolls" perk for rope breakage.

I like that one.