MELEE COMBAT SYSTEM:
Used keys - Q,E,T,Z,C,LMB,RMB,LALT,TAB (different for people who use the num pad)
HAND-TO-HAND
LMB - punch ; RMB - kick (away from character) ; Q - grapple enemy ; E - sweeping kick ; ALT - blocking stance (with all other mentioned keys being modifiers to block a particular type of melee attack) ; C - counter ; Z - uppercut ; TAB - dodge
MELEE WEAPON
LMB - swing ; RMB - thrust ; E - stun move (use the non-blade side of the weapon) ; Q - grapple enemy ; ALT - blocking stance (with all other mentioned keys being modifiers to block a particular type of melee attack) ; C - counter ; Z - kick ; TAB - dodge
FIREARMS
Q,E - lean around cover
LMB - shoot ; RMB - aim down sights ; Z - bash with the stock of the weapon / with your fist for pistols ; C - use bayonet ; ALT - blocking stance (with all other mentioned keys being modifiers to block a particular type of melee attack) ; TAB - dodge
BOWS & CROSSBOWS
Q,E - lean around cover
LMB - shoot (hold for more powerful shot) ; RMB - aim ; Z - bash ; C - use weapon special (like thorns on a bow) ; ALT - blocking stance (with all other mentioned keys being modifiers to block a particular type of melee attack) ; TAB - dodge
ARM-MOUNTED CROSSBOWS
Q,E - lean around cover
LMB - shoot crossbow ; RMB - aim crossbow ; Z - punch ; C - kick ; ALT - blocking stance (with all other mentioned keys being modifiers to block a particular type of melee attack) ; TAB - dodge
Why didn't I use F, X and the middle mouse button? F is "Interact", X is "change firemode" on firearms and the middle mouse button is just generally horrible game design (it never works when it's supposed to, for one thing).