Encounter Mode

When the GM calls for it, you'll roll initiative to determine your place in the initiative order, which is the sequence in which the encounter's participants will take their turns. Rolling initiative marks the start of an encounter. More often than not, you'll roll initiative when you enter a battle.
Typically, you'll roll a Perception check to determine your initiative—the more aware you are of your surroundings, the more quickly you can respond. Sometimes, though, the GM might call on you to roll some other type of check. For instance, if you were Avoiding Notice during exploration, you'd roll a Stealth check. A social encounter could call for a Deception or Diplomacy check. In most cases, you can still use Perception if you prefer.
The GM rolls initiative for anyone other than the player characters in the encounter. If these include a number of identical creatures, the GM could roll once for the group as a whole and have them take their turns within the group in any order. However, this can make battles less predictable and more dangerous, so the GM might want to roll initiative for some or all creatures individually unless it's too much of a burden.
Unlike a check, where the result is compared to a DC, the results of initiative rolls are ranked. This ranking sets the order in which the encounter's participants act—the initiative order. The character with the highest result goes first. The second highest follows, and so on until whoever had the lowest result takes their turn last.
If your result is tied with an enemy's result, the enemy goes first. If your result is tied with another PC's, you can decide between yourselves who goes first when you reach that place in the initiative order. After that, your places in the initiative order usually don't change during the encounter. (But see the Delay basic action.)

A round begins when the participant with the highest initiative roll result starts their turn, and it ends when the one with the lowest initiative ends their turn. The process of taking a turn is detailed below. Creatures might also act outside their turns with reactions and free actions.

Once everyone in the encounter has taken a turn, the round is over and the next one begins. Don't roll initiative again; the new round proceeds in the same order as the previous one, repeating the cycle until the encounter ends.

When your foes are defeated, some sort of truce is reached, or some other event or circumstance ends the combat, the encounter is over. You and the other participants no longer follow the initiative order, and a more free-form style of play resumes, with the game typically moving into exploration mode. Sometimes, at the end of an encounter, the GM will award Experience Points to the party or you'll find treasure to divvy up.

Many things happen automatically at the start of your turn— it's a common point for tracking the passage of time for effects that last multiple rounds. At the start of each of your turns, take these steps in any order you choose.

• If you created an effect lasting for a certain number of rounds, reduce the number of rounds remaining by 1. The effect ends if the duration is reduced to 0. For example, if you cast a spell that lasts 3 rounds on yourself during your first turn of a fight, it would affect you during that turn, decrease to 2 rounds of duration at the start of your second turn, decrease to 1 round of duration at the start of your third turn, and expire at the start of your fourth turn.
• You can use 1 free action or reaction with a trigger of “Your turn begins” or something similar.
• If you're dying, roll a recovery check.
• Do anything else that's specified to happen at the start of your turn, such as regaining Hit Points from fast healing or regeneration.

The last step of starting your turn is always the same.

• Regain your 3 actions and 1 reaction. If you haven't spent your reaction from your last turn, you lose it—you can't “save” actions or reactions from one turn to use during the next turn. Some abilities or conditions (such as quickened, slowed, and stunned) can change how many actions you regain and whether you regain your reaction. (Details on gaining and losing actions are here.)

You can use actions in any order you wish during your turn, but you have to complete one action or activity before beginning another; for example, you can't use a single action in the middle of performing a 2-action activity. What actions you can use often depend on your class features, skills, feats, and items, but there are default actions anyone can use, described in Basic Actions. Some effects might prevent you from acting. If you can't act, you can't use any actions, including reactions and free actions.
If you begin a 2-action or 3-action activity on your turn, you must be able to complete it on your turn. You can't, for example, begin to High Jump using your final action on one turn and then complete it as your first action on your next turn.
Once you've spent all three of your actions, your turn ends (as described in Step 3) and the next creature's turn begins. You can choose to end your turn early, losing all remaining actions (but not your reaction).

Once you've done all the things you want to do with the actions you have available, you reach the end of your turn. Take the following steps in any order you choose. Play then proceeds to the next creature in the initiative order.

• End any effects that last until the end of your turn. For example, spells with a sustained duration end at the end of your turn unless you used the Sustain a Spell action during your turn to extend them. Some effects caused by enemies might also last through a certain number of your turns, and you decrease the remaining duration by 1 during this step, ending the effect if its duration is reduced to 0.
• If you have a persistent damage condition, you take the damage at this point. After you take the damage, you can attempt the flat check (in the sidebar) to end the persistent damage. You then attempt any saving throws for ongoing afflictions. Many other conditions change at the end of your turn, such as the frightened condition decreasing in severity. These take place after you've taken any persistent damage, attempted flat checks to end the persistent damage, and attempted saves against any afflictions.
• You can use 1 free action or reaction with a trigger of “Your turn ends” or something similar.
• Resolve anything else specified to happen at the end of your turn.

You can ride some creatures into combat. As noted in the Mount specialty basic action, your mount needs to be willing and at least one size larger than you. Your mount acts on your initiative. You must use the Command an Animal action to get your mount to spend its actions. If you don't, the animal wastes its actions. If you have the Ride general feat, you succeed automatically when you Command an Animal that's your mount.
For example, if you're mounted on an animal and you make three attacks, your mount would remain stationary since you didn't command it. If you instead spent your first action to Command an Animal and succeeded, you could get your mount to Stride. You could spend your next action to attack or to command the mount to attack, but not both.

Many monsters can fly, and PCs can use spells and items to gain the ability to fly. Flying creatures have to use the Fly action to move through the air. Performing an especially tricky maneuver might require using Acrobatics to Maneuver in Flight. Creatures might fall from the sky, using the falling rules. At the GM's discretion, some groundbased actions might not work in the air. For instance, a flying creature couldn't Leap.

Use these rules for battles in water or underwater.

• You're off-guard unless you have a swim Speed.
• You gain resistance 5 to acid and fire.
• You take a –2 circumstance penalty to your attack rolls for bludgeoning or slashing attacks that pass through water.
• Ranged attacks made by an underwater creature or against an underwater target have their range increments halved.
• You can't cast fire spells or use actions with the fire trait underwater. As normal for how traits work, any part of the effect that's unrelated to fire still works. For example, an attack with a flaming fangblade could still deal its physical damage, just not its fire damage.
• At the GM's discretion, some ground-based actions might not work underwater or while floating.