While it is a trivialistic d20 rulesystem, I love how in SWKotoR you can stack Master Critical Strike and Keen on dual lightsabers (need the appropiate endgame crystals though) and get a critical hit on 11-20, i.e. over 50% of the time (since rolling 1 is a critical miss):
Lightsabers crits on 19-20 (thus one uses dual lightsabers and not a twohanded lightsaber, which only crits on 20)
Keen Lightsaber would double the base crit range, thus crit 17-20 (while keen twohanded lightsaber would only crit 19-20)
"Regular" Critical Strike would add another extension: 15-20
Improved Critical Strike would do the same again: 13-10
Finally Master Critical Strike did this the third time: 11-20
That was pretty wicked. Some opponents would unfortunately be immune to critical hits, though.
Even worse, if you made a Strength focused build, well Strength would decide how hard the DC to also stun opponents would be. Again certain opponents would be immune to that, too.
All in all Critical Strike was so overpowered, and definitely better than the other two choices for weapon attack style, except if you faced opponents with immunities (not that often).
Flurry instead would give you another attack. Not impressive with Dualwielding and Master Speed (4 attacks total).
Power Attack gave you extra damage per attack. With the best gear and Master Speed, it was about as good as Flurry.
Never seen anything like this in any other game.
In BG3 and D&D5 unfortunately all weapons naturally only crit on a 20, and I dont think there is even a single keen weapon in the game (?). Fortunately as people mentioned certain states such as paralyzed allow you to always autocrit anyway.
