Using half rounds for combat can add granularity and tension to combat encounters in your 5th edition D&D campaign.
A standard round is 6 seconds, and each creature acts once per round in initiative order (a creature’s turn). Half rounds divide that round into two 3-second phases:
• Phase A and Phase B
This allows for two opportunities to act per round with a movement and possible bonus action or by taking an action. How a creature may act is limited per phase dependent on the choice of which opportunity to act is taken first.
This allows for two opportunities to act per round with a movement and possible bonus action or by taking an action. How a creature may act is limited per phase dependent on the choice of which opportunity to act is taken first.
Mechanics
1. Initiative
• Roll initiative as normal.
• Each round is split into two phases.
• Each phase is taken in initiative order.
2. Action Economy Per Phase
Generally split actions like this:
Phase Allowed Actions
A Movement + Bonus Action
B Action or Reaction Setup
2. Action Economy Per Phase
Generally split actions like this:
Phase Allowed Actions
A Movement + Bonus Action
B Action or Reaction Setup
Or:
Phase Allowed Actions
A Action or Reaction Setup
B Movement + Bonus Action
This motivates players to plan ahead, creating tactical depth.
This motivates players to plan ahead, creating tactical depth.
Creatures move or take an action in either phase, but if movement is split before and after an action, the action will start in Phase A, and occur in Phase B.
3. Spellcasting
• Spells with casting time of 1 action occur at the end of a Phase/3 seconds.
• Concentration checks and reactions can occur during either phase.
4. Reactions
Reactions still occur outside a creature's turn during any phase of an opponent's subsequent turn, or during a subsequent phase of the creature reacting.
5. Status Effects
• Effects like “stunned until end of next turn” now last two phases.
• Conditions should be clarified to specify which phase they end on.
3. Spellcasting
• Spells with casting time of 1 action occur at the end of a Phase/3 seconds.
• Concentration checks and reactions can occur during either phase.
4. Reactions
Reactions still occur outside a creature's turn during any phase of an opponent's subsequent turn, or during a subsequent phase of the creature reacting.
5. Status Effects
• Effects like “stunned until end of next turn” now last two phases.
• Conditions should be clarified to specify which phase they end on.
Pros
• More tactical combat: Players must think in smaller increments.
• Faster pacing: Movement and action separation speeds up decision-making.
• Cinematic feel: Feels like bullet-time or split-second dueling.
Cons
• Complexity: More tracking for DMs and players.
• Balance issues: Some classes (e.g., monks, rogues) may benefit disproportionately.
• Longer combats: More phases can mean more time per encounter.
• Complexity: More tracking for DMs and players.
• Balance issues: Some classes (e.g., monks, rogues) may benefit disproportionately.
• Longer combats: More phases can mean more time per encounter.
Options
• Legendary Creatures: Give them actions in both phases to emphasize threat.
• Initiative Time Drift: Shift a creature’s turn to start 1 second later per each 5 points of initiative less than the highest initiative score.
• Environmental Effects: Trigger hazards or changes between phases.