It's not that hard. In a given round, you can do exactly
one of the following:
- One full-round action
- One standard action, plus a move action
- Two move actions
Making multiple melee attacks, the "full attack" maneuver, is a full-round action.
Making a
single melee attack is a standard action.
Casting a regular spell is a standard action.
Moving your speed is a move action.
SquidSonata said:
--If you have multiple attacks (BAB 6+), you can still only cast one spell (except for free-action spells like feather fall) during your turn. So if you choose the full-attack option, you are unable to cast a spell (but you get two melee/ranged attacks). Correct?
Yes.
If you choose to cast a spell, that is your single standard action.
If you instead choose to make your two weapon attacks, that is your single full-round action.
You can't do both in the same round.
--If you have multiple attacks, (BAB 6+), and you choose the full-attack option, you cannot cast a spell and make a melee/ranged attack. Correct?
Yes.
Casting a spell would be a standard action by itself.
Making a single melee attack would also be a standard action.
You can't do both in the same round.
--If you are hasted, you can only cast one spell (not two). The spell cast costs a standard action, so then you have a partial action to do something else. Correct?
Almost.
If you take a standard action, you have a move action left. That lets you move your speed (30' for an unencumbered human), or do a few other things that take little time (like drawing a weapon).
"Partial action" is an old term from 3.0. It was bizarre and confusing, so the term doesn't exist anymore. Pretend you never saw it.