Spinning off this same idea.
I was thinking of Allowing the attacker to adjust crit rolls, up or down, by 1 or 2 points per rank in the skill.
Yes combat can be random, but the more skilled a Fighter is, I believe the more they are able to reduce that randomness.
What are others thoughts on these ideas?
I've been thinking about this topic on and off since you posted it and it's been an interesting approach. If the argument is that RM is too randomly deadly, then allowing the PC to directly modify the crit roll, makes it specifically more deadly. The Ambush skill allows the user to directly modify a crit roll already. If you employ your option of allowing even 1 point per skill rank, a person with 5 skills ranks can modify +/- 5 giving the player a differential of 10 to score a "66-Crit". A roll of 61-71 can now be made into a 66 which is pretty frequently a final blow to a target.
Along those lines of allowing skill to come into play though, I came up with a few options to allow Critical Striking Skill to be included. And, as with any RM optional rule, it's an optional rule.
1) Allow only increases to the critical roll per skill rank. 5 skill ranks = +1 to +5 increase to the crit roll. This only imparts 5 more chances to get the "66-crit"
2) Allow only maximum skill rank to crit roll. 5 skill ranks = +5 to crit roll. This only imparts 1 more chance to get a 66. 61 or a 66
3) Allow the user the ability to reroll a crit #of ranks/5 (or #/3) round down. 5 skill ranks = 1 chance to reroll the crit.
A) Take the better of the 2 rolls
B) Must take the new crit roll even if it's worse than the first crit roll
I like the randomness of battle and consequences of snap decisions in the heat of battle with option 3. Options 1 and 2 are too similar to the Ambush skill, but if I had to choose, I would opt for option 2. I still want it to be difficult to get the yummy "66" on the crit table. By allowing for a range of 11 chances (or more) to hit a 66, the excitement and rush of rolling that awesome crit is diminished. The goal was to "reduce lethality and bring skill into the effect". You can't make it overly easy to get the lethal crit rolls.
At the very least, I would make learning that skill nearly cost prohibitive. DP cost of 10 for Arms users and DP=20 for Semi-Spell users, DP=30 for Spell users. The rationale being, how do you know you are actually improving your critical strike by twisting this way or that way, or sliding up and over like this, or whatever technique is used without actually practicing it on someone or something? You would go through slaughtering a lot of animals, or worse, people, trying to improve that particular Deadly Skill. Unless maybe, you are a professional butcher who decides to go adventuring some day.