Free DND Encounter Builder
A DND encounter builder helps dungeon masters create balanced 5e combat encounters from party size, average level, difficulty, terrain, and monster theme. Use this free tool to calculate XP budgets, generate a monster roster, and copy table-ready tactics into your notes.
Built for session prep and quick table pivots
Build an encounter before game night, then adjust party size, level, terrain, or creature count if the players take a different route mid-session.
Find board games with GameShelfTarget budget
2,000
adjusted XP
Built encounter
2,050
adjusted XP
Multiplier
x2
5 creatures
Fit
102%
Close to target
Encounter roster
Medium Mixed fantasy encounter
1x Skeleton archer screen
CR 1/4 - Ranged pressure - 50 XP each
Open from cover, then split fire between healers and exposed casters.
1x Goblin skirmisher
CR 1/4 - Mobile minion - 50 XP each
Hide, disengage, and force the party to waste actions chasing them.
1x Giant spider
CR 1 - Web lockdown - 200 XP each
Webs the front line and climbs out of melee reach.
1x Veteran mercenary
CR 3 - Elite bruiser - 700 XP each
Locks down the strongest melee character while minions pressure the backline.
1x Kobold trap runner
CR 1/8 - Hazard support - 25 XP each
Kites the party through alarms, loose stones, and prepared hazards.
Frequently asked questions
What is a DND encounter builder?
A DND encounter builder is a tool that helps dungeon masters choose monsters and XP budgets for a combat scene based on party level, party size, and desired difficulty.
How does this DND encounter calculator balance combat?
It uses 5e character XP thresholds for easy, medium, hard, and deadly encounters, then applies the standard adjusted XP multiplier for multiple monsters.
Can I choose terrain and monster themes?
Yes. Pick terrain such as dungeon, forest, city, desert, arctic, or swamp, then choose a theme like undead, goblinoid, beasts, cultists, dragons, or mixed fantasy.
Should every encounter match the XP budget exactly?
No. The XP budget is a useful planning target, but terrain, surprise, magic items, healing, player tactics, and rest timing can change real table difficulty.
Does this tool require a GameShelf account?
No. The DND encounter builder is free and runs in your browser without signup.