"The game the way it used to be — with one check mechanic for everything."
Castles & Crusades is the feel of AD&D on a d20 chassis, with one brilliant simplification: the SIEGE engine resolves every check with a single mechanic. Published by Troll Lord Games since 2004 with input from original D&D authors (Gary Gygax consulted). A bridge between old-school play and clean modern design — not strict OSR, but cut from the same cloth.
Setting-agnostic, with an implied classic fantasy (the official setting is Aihrde). Knights, dungeons, dragons, and ancient ruins. The spirit is old-school heroic adventure: explore, fight, grow rich. It runs virtually any AD&D or OSR module with almost no conversion.
The SIEGE Engine
Every check is one mechanic: d20 + level + modifier against a Challenge Base (12 for a prime attribute, 18 otherwise) plus the challenge level. Learnable in fifteen minutes.
Prime Attributes
Each character marks some abilities as 'prime' — checks against them are easier. This defines what a hero is good at without bloated skill lists.
AD&D feel on d20
Classes, levels, AC, familiar ancestries. If you've played AD&D or 3e, you already know the base. Old-school lethality and exploration in a modern presentation.
Speed at the table
Built for pace: minimal rulebook lookups, quick Castle Keeper rulings. 'D&D the way it used to be' — without build analysis paralysis.
Open in Session Zero to let every player vote and see the results.