- I can use the d6 damage or effects roll;
- more damaging hits are now also more likely to cause a failed save;
- tripling a number isn't too hard;
- "less than but NOT equal" means that ability 18 still leaves a 1 in 6 chance of failure, if unmodified.
Also, something like "Strength 14 (4)" could be used as a limit in some cases: roll a d6, but count 5 or 6 as a maximum result of 4. Maybe strangulation or squeezing to crush an opponent is limited to this Strength rating.
The 3-18 scores still apply, however, when comparing two opponents. A contest between a Strength 13 and a Strength 14 wrestler would give the second wrestler a +1 advantage, even though both have the same saving throw rating.
I'll have to think about this more.