#5e

Dungeons & Dragons 5th-edition encounter-building maths as an API, computed locally and deterministically — the XP-budget and difficulty numbers a Dungeon Master balances a fight with. The budget endpoint sums the per-character XP thresholds from the DMG across the party — by party size and level, or a list of mixed levels — to give the easy, medium, hard and deadly budget for one encounter (a party of four 5th-level characters has thresholds of 1,000 / 2,000 / 3,000 / 4,400 XP), plus the total adventuring-day budget. The difficulty endpoint rates an encounter: it sums the monsters' XP, multiplies by the encounter multiplier for the number of monsters (×1.5 for two, ×2 for three to six, up to ×4 for fifteen or more), and compares the adjusted XP to the party thresholds — four 450-XP monsters against that party come to 3,600 adjusted XP, a hard fight. The carry endpoint gives the carrying capacity (Strength × 15, scaled by size), push/drag/lift and the encumbrance thresholds. Everything is computed locally and deterministically, so it is instant and private. Ideal for tabletop, virtual-tabletop, DM-tool and TTRPG app developers, encounter-builder and balance tools, and game-master education. Pure local computation — no key, no third-party service, instant. Uses the DMG tables. Live, nothing stored. 3 compute endpoints. For monster stats and spells use a D&D SRD data API.

api.oanor.com/dndencounter-api

The complete Dungeons & Dragons 5th-edition System Reference Document as an API — spells, monsters, classes, subclasses, races, backgrounds, equipment, magic items, conditions, features, feats, skills and the full rules reference. Look up a spell by name (e.g. Fireball → 3rd-level evocation, 150 ft, 8d6 fire) or a monster statblock (e.g. Adult Red Dragon → CR 17, AC 19, 256 HP, legendary actions), list and filter any resource type (spells by level or school, monsters by challenge rating), or fetch full detail for any of the 24 SRD categories. Backed by the open dnd5eapi.co dataset. Ideal for character builders, virtual tabletops, encounter and spell-card generators, Discord bots and homebrew tools.

api.oanor.com/dnd-api