Howdy!
There has been some mention, especially since the “Fatigue” update, that armor resistance would be best represented as a critical hit mitigation rather than as a Fatigue prevention (if anything, heavy armor should make its wearer tire faster). But doing so shakes the overall balance of damage ratings, Resilience, Deadliness and other harm elements of the rules. So here is another take that might help keep things in shape, and reduce the amount of dice rolling in the process.
1) No more armor Resistance to regular damage - this means that it’s faster to have one’s Resilience exceeded. So instead, add the highest skill score among Fitness, Tactics, Martial Arts (melee or unarmed) to the character’s Resilience total . It also answers another recurring comment that skill at arms should help mitigate the risk of being wounded. You'll still run a bit faster into the Incapacitated condition, but I'm not against making fights a bit swifter. Other side effects: no more weirdness of being able to land a critical strike with an attack that does zero physical damage with a double opportunity; and it is nigh impossible to trigger the negative effect of the Razor-Edged weapon quality --> cf. #4 for that last bit.
2) No more Fitness roll to reduce a crit severity! This is my favorite as this roll does get in the way of free flow action in skirmishes. Instead, reduce the severity by [Armor Resistance rating + the Ring of the stance the target is in] . You still tie this to a Ring that scales as characters progress and determines which of the critical strike's effects applies. If the target cannot take a stance (unconscious or for other reason), they don't get the benefit of the Ring reduction, and the attacker chooses the effect when several are possible.
3) I am aware #2 will reduce crit severity further than the typical number of successes one would get on a Fitness check, so I am inclined to a) bump up the Deadliness of all weapons by 2 and b) decrease armors' Physical Resistance values by 1 (to a minimum 0) . This way, someone in Ashigaru Armor will typically end up with more or less the same crit severity as they do in the current system; those with less armor will suffer more and those with heavier gear will suffer less.
4) Add two levels to the table of critical strikes results below the "0" entry as follows . residual Severity after modifiers is -1: nothing happens (no lucky opportunistic destruction of armor with a phony crit); If Severity after mods is -2 or lower: same as -1, but if the weapon is Razor-Edged, it gets the Damaged quality. It brings back what my #1 took away, while making it much less likely and more difficult to metagame (e.g. by failing the attack on purpose to avoid damaging your weapon... you can still do that, but that requires knowing the opponent's Ring values). Note that the Update 2.0 also helps by allowing Razor-Edged weapons to increase Deadliness by way of opportunities expenditures.
Thoughts? Any other bases that need to be covered?