All engagements using Turn-Based Action consist of two phases: The Set-Up and Initiative Rounds. The set-up phase establishes the status and order of the participants and the amount of time each round takes in the game world, and initiative rounds are where the participants take their turns round after round until one side is victorious.
The Set-Up Phase consists of three principle steps: Setting the Scene, Surprise & Sudden Actions, and finally Establishing Initiative.
The DM establishes the conditions of any Turn-Based Action encounter. This includes the known participants and their positions, any active elements and known environmental effects (Positive or Negative) in the scene, and the length of each round.
A round encompasses the semi-simultaneous actions of the participants within a period of game world time. For combat, one round is usually 6
seconds. In other cases a round might take 10 seconds, 1 minute, or 10 minutes as deemed appropriate by the DM for a given scene.
The party lurks in the shadows of the cult’s ritual, looking for the right moment to cut it short.
A sneaky athlete sprints ahead before the start of the race and the other racers catch on.
A noble suddenly draws her sword and lunges at the king.
If some participants are unaware of others due to successful attempts to be stealthy, they begin the encounter surprised. The DM calls for appropriate ability checks to determine whether participants are aware of each other. Surprised creatures are unable to move or take an action on their first turn, and are unable to use a reaction until after their first turn.
Hidden Attacker
When you are hidden from a target, you gain advantage on your first attack roll against it. After your first attack roll, unless you are invisible or your target is otherwise unable to see you, you are no longer hidden.
Sometimes all participants are aware of each other at the beginning of an encounter, but one side takes an action or launches an attack while others’ guards are down. In this case, no one is surprised, but the DM may allow the instigating creature or party to roll initiative with advantage.
If nobody is trying to be sneaky, combat begins normally with initiative as described below.
Establishing initiative sets the order of everyone’s turn throughout the encounter. Each participant makes an ability check to determine their place in the initiative count, from the highest check total to the lowest.
This ability check is typically made with Dexterity, but The DM might determine that one or more participants should instead roll a different ability check, potentially even utilizing a relevant skill or tool. Some suggestions are listed below, in the Types of Initiative Table, though the list is by no means exhaustive.
| Types of Initiative | |
| Possible Scenario | Potential Ability Check |
| Spotting a hidden threat | Wisdom (Perception) |
| Climbing a cliff during a landslide | Strength (Athletics) |
| Acting unassuming before taking sudden action | Charisma (Deception) |
| Noticing when an unassuming character is about to take action | Wisdom (Insight) |
| Participating in a wagon race | Dexterity (Land Vehicles) |
In the event of a tie, the DM decides the order among tied DM-controled creatures, and players decide the order among their tied characters. The DM can decide the order if the tie is between a monster and a player character.
Some examples of how to adjudicate ties in Initiative include:
Once Initiative order has been established, the scene plays out as follows: World Actions, Character/Monster Turns, and the End of Round.
The battlefield itself can be as active a participant in Turn-Based Action as the characters are, and its actions can have serious consequences for everyone involved. A raging storm might threaten to blow characters off their feet, while lightning splits the ground around them, Souls lost to the sea might attempt hamper the characters aboard a ship at sea, and so on.
Environmental effects like these, or lair actions that accompany particularly powerful monsters, always occur a tthe start of each round before any participants act. The DM determines if any participants are within the range of these effects, and adjudicates the results accordingly.
During a participant's turn, they can move a distance up to their Speed--sometimes called your walking speed--and take their actions. The intent for a participant's actions can be declared in any order, breaking up their movement between actions or using their bonus action first. Or they can also choose to do absolutely nothing.
Within a single round, a participant can take an action, a bonus action, and any free actions (like communicating with allies, dismissing the effect of a thaumaturgy cantrip they already cast, or interacting with an object) during their turn, and one reaction at any time. The rules for actions and movement are found in the Actions in Combat and Movement and Position sections, respectively.
Once all participants have taken their turn, the encounter returns to the start of a new round. The loop persists until the action concludes, or the granularity of Turn-Based Action is no longer needed.