I'm curious about moving in threatened squares, say I'm a fighter and I'm already in a square fighting a monster with normal melee range and I move to the opposite side of him so that an ally can move where I was and gain combat advantage against the monster. Do I provoke an Opportunity Attack because I left a threatened square or do I not since I still within the area of his threatened reach? Or, to put it another way, is it leaving the square or leaving or leaving his reach that gives him the opportunity attack or is that my DM's choice?
[RPG] Attacks of Opportunity from moving within a threatened area
combat-advantagednd-4emovementopportunity-attack
Related Solutions
Sorry, one movement only provokes one AoO from a given defender.
See the d20pfsrd:
If you have the Combat Reflexes feat, you can add your Dexterity modifier to the number of attacks of opportunity you can make in a round. This feat does not let you make more than one attack for a given opportunity, but if the same opponent provokes two attacks of opportunity from you, you could make two separate attacks of opportunity (since each one represents a different opportunity). Moving out of more than one square threatened by the same opponent in the same round doesn't count as more than one opportunity for that opponent. All these attacks are at your full normal attack bonus.
So if you shriek "SERPENTINE!!!" and run circles around your opponent, they still only get one "leaving a threatened square" AoO on you.
The opportunity from Hold the Line is different, but only works once upon them entering your threatened area. So you would get only one from Hold the Line and one for them leaving a threatened square.
Note that the leaving a threatened square is per round - not even just per turn - with the Mythic rules in use in our WotR campaign we've been finding a lot of cases where you get to act multiple times in a round, even charge multiple times, etc. If by hook or crook someone charged you, ran off, charged you again, and ran off again over the course of a round (on their turn or across multiple turns), you would still only get 1 AoO for them leaving your threat but could get multiple from Hold the Line, if they actually leave and enter your threatened area with a charge twice. Up to the limit of the number of AoOs you have.
A creature that, because of the creature's size, provokes attacks of opportunity for entering a foe's square provokes attacks of opportunity when entering that foe's square even if the creature enters that square by taking a 5-ft. step...
The rules cited in the question are from two different places about two different things. The 5-ft. step rules don't care about the creature size rules, and the creature size rules don't care about the 5-ft. step rules. The two rules are managed independently and don't interact. Thus, when a Tiny, Diminutive, or Fine creature enters an opponent's square, it provokes an attack of opportunity even if it entered that opponent's square by taking a 5-ft. step. That's a function of the creature's size exclusive of the creature's 5-ft. step.
Example 1
A Tiny, Diminutive, or Fine creature takes a 5-ft. step when adjacent to opponent and within that opponent's threatened area that doesn't provoke an attack of opportunity (because of the 5 ft. step) and moves into his opponent's square which does provoke attacks of opportunity (because of the creature's size).
When a Tiny, Diminutive, or Fine creature takes a move action to move within its opponent's threatened area then enter its opponent's space, the creature probably should provoke attacks of opportunity twice, once for the movement within the creature's threatened area and once for entering the creature's square, except that the FAQ (see below) says to treat the opportunity granted by moving within a creature's threatened area as part of the same movement needed to enter a creature's space. Thus a typical Medium creature gains only one attack of opportunity against a Tiny foe that takes a move action to enter the creature's square.
Example 2
A Tiny, Diminutive, or Fine creature takes a move action to travel 30 ft. to enter an opponent's square. The creature provokes an attack of opportunity when moving within the opponent's threatened area as normal then can enter the opponent's square with impunity.
It's sort unfortunate that two attacks of opportunity aren't provoked. It might've saved the Dexterity 13 commoner with the feat Combat Reflexes from death by house cat.
...And the FAQ agrees
The Pathfinder Roleplaying Game Core Rulebook FAQ contains the following exchange:
Question: In the section on Tiny and smaller creatures, it says that entering a creature’s space provokes an attack of opportunity, but typically 5-foot steps don’t provoke an attack of opportunity. If a Tiny or smaller creature took a 5-foot step into a creature’s space, would it provoke an attack of opportunity?
Answer: Yes. Even with a 5-foot step, a Tiny or smaller creature entering a creature’s space provokes an attack of opportunity (unless it is using a more specific ability to avoid the attack of opportunity such as the Monkey Shine feat). This doesn’t mean that a Tiny or smaller creature entering a creature’s space and moving out of a threatened square with a move action provokes two attacks of opportunity from that creature, for the same reason that moving out of multiple of a creature’s threatened squares in the same move action doesn’t provoke two attacks of opportunity.
This exchange was added to the FAQ in Jan. 2016.
Best Answer
Opportunity attacks are interrupts triggered by attempting to leave an adjacent square
"Leaving an adjacent square to enter another adjacent square" is just as much "leaving an adjacent square" as is "leaving an adjacent square to enter a non-adjacent square." It's not about leaving his reach entirely, it's about leaving a square he threatens.
If I'm leaving an adjacent square, that's all that's needed to trigger the OA. The attacker doesn't care where I'm going, just if the square I'm leaving is one he threatens.
[Of course, each creature only gets one opportunity action per turn, so even if I move through three of his threatened squares on my turn he can only make one opportunity attack against me.]