As part of a set of houserules I'm working on, I've been heavily tweaking the combat action system with two aims; first, to simplify the system as a whole, and second, to provide greater tactical mobility in melee and less tactical mobility for casters and ranged attackers who wind up in melee. Here's what I have currently:
There are five action types: double, single, swift, free, and immediate. You can perform one double or two single, as well as a swift and any number of free actions on your turn.
Threatened Area and AoO: Movement only provokes an AoO if you leave an enemy's threatened area.
Attack: You can make one attack as a single action. This action is non-repeatable; to spend the whole round attacking, use the full attack action.
Full Attack: You can make all of your attacks as a double action. You may move up to half your speed at any point before, between, or after these attacks. If you do not have multiple attacks, you can instead make a single attack with +2 to hit.
Cast a Spell: Spells require a double action to cast.
Withdraw: As a single action, you can move half your speed and not take AoO for leaving the space you started in.
Almost all other actions (move, draw a weapon, drink a potion) are single actions. 5-ft steps are no more; a caster or archer in melee must use the withdraw action, after which the caster can begin casting (but remains vulnerable to interruption, as they must finish the spell the following round) and the archer can make a single attack.
Feedback on any part is welcome, but I'd particularly appreciate any comments regarding the withdraw action/movement as part of a full attack/removal of 5 ft step--it doesn't feel quite right yet.
Just at a glance, I'm confused by one thing
Threatened Area and AoO: You only provoke an AoO by leaving an enemy's threatened area.
and
5-ft steps are no more; a caster or archer in melee must use the withdraw action, after which the caster can begin casting
Based on the above, a caster or archer in melee needn't withdraw, because they don't leave an enemy's threatened area.
Just at a glance, I'm confused by one thing
Threatened Area and AoO: You only provoke an AoO by leaving an enemy's threatened area.and
5-ft steps are no more; a caster or archer in melee must use the withdraw action, after which the caster can begin castingBased on the above, a caster or archer in melee needn't withdraw, because they don't leave an enemy's threatened area.
Oops; what that's meant to say is that movement only provokes if you leave the threatened area. Casting, shooting, potion-drinking, etc all still provoke normally. I've edited the OP to reflect that.