|d20 Modern System Reference Document|
SPECIAL INITIATIVE ACTIONS
Usually a character acts as soon as he or she can in combat, but sometimes a character wants to act later, at a better time, or in response to the actions of someone else.
By choosing to delay, the character takes no action and then acts normally at whatever point in the initiative count the character decides to act. When a character delays, he or she voluntarily reduces his or her own initiative result for the rest of the combat. When the character’s new, lower initiative count comes up later in the same round, the character can act normally. The character can specify this new initiative result or just wait until some time later in the round and act then, thus fixing the character’s new initiative count at that point.
A character cannot interrupt anyone’s action with a delayed action (as a character can with a readied action; see below).
The longest a character can delay before taking an action is until after everyone else has acted in the round. At that point, the delaying character must act or else forfeit any action in that round.
If multiple characters are delaying, the one with the highest initiative modifier (or highest Dexterity, in case of a tie) has the advantage. If two or more delaying characters both want to act on the same initiative count, the one with the highest initiative modifier gets to go first. If two or more delaying characters are trying to go after one another, the one with the highest initiative modifier gets to go last; the others must go first or lose their action for the round.
If a character loses an action due to delaying, he or she may act on any count on the next turn. Again, the character cannot interrupt an action.
The ready action lets a character prepare to take an action later, to interrupt another character. Essentially, the character splits his or her action, taking the move action on the character’s initiative count and the attack action at a later point. On the character’s turn, he or she prepares to take an action later, if a specific trigger is met. Then, later in the round, if the readied action is triggered, the character takes it, acting before the triggering action.
Readying does not provoke an attack of opportunity. (The character’s move action, and the attack action he or she readies, may both provoke attacks of opportunity normally.)
Readying an Action
A character can ready an attack action or a move action. To do so, the character specifies the action he or she will take and the conditions under which the character will take it. Then, any time before the character’s next action, the character may take the readied attack action in response to those conditions. The readied action occurs just before the event that triggers it. If the trigger is part of another character’s actions, the readied action interrupts the other character. The other character continues his or her actions once the readied action is completed.
The character’s initiative count changes. For the rest of the encounter, it is the count on which the character took the readied action, and the character acts immediately ahead of the character whose action triggered the readied action.
A character can take a 5-foot step as part of his or her readied action, but only if the character didn’t otherwise move any distance during the round.
If the character comes to his or her next action and has not yet performed the readied action, the character doesn’t get to take the readied action (though the character can ready the same action again). If the character takes his or her readied action in the next round, before his or her regular turn comes up, the character’s initiative count rises to that new point in the order of battle, and he or she does not get your regular action that round.