As I mentioned before, it should not be a big time investment - since that particular part about miss/hit chance calculation should be practically unchanged. Only result of that calculation would be used differently.
Regarding crits, I intentionally did not include them in my proposal since players are not annoyed if they get crit. So crits could go as usual, either in variant of dealing 2* average damage, or even remaining exactly as original and doing 2* random 1-12 plus mods damage just as they do now ... in other words, when crit happen, it could deal double max damage just as it does now. Leaving crits as they are now is one of the reasons I called this suggestion "reducing" randomness, instead of "eliminating" randomness - but I guess I could have explained that better in OP.
There should be never situation where "having no chance to crit will make combat longer" - even if someone want crits included in average, then those averages would need to be multiplied by (1+ pHit%*critMult) so that each average hit is slightly increased by average crits. But , as I said, there is no reason to change crits - they can keep working as they do now, and still average damage over entire fight will be exactly same for my suggestion. So fight would not be longer, with any valid 'average' implementation, either one with no crits and crits included in average , or one I'm suggesting where crits remain outside of averages.
Regarding "keep concentrating", I also did not propose change in how enemies fight - their damage should still keep being exactly same as now, with full random range and possibility to miss - after all, NPC enemies do not get annoyed by misses.
To recap, all these points have "remains same as it is now" in common :
- attack roll (miss calculation) remains practically identical, only its result is used differently
- crits remain unchanged even with my suggested option enabled ( they are not included in average attack values, so when player crit it does same random double range damage as now )
- enemy damage remains completely same as now - even with my suggested option enabled - since enemies are not annoyed by misses
- fight duration ( average number of rounds ) remains same as it is now
- possibility to end fight in one lucky round due to big crit remains
You want the AI enemy to miss you while you never miss them. So, you want an easier difficulty. I'm sure Larian already has one in their roadmap.
