d20systemet

The d20 System is a role-playing game system originally developed by Wizards of the Coast for Dungeons & Dragons 3rd edition, released in 2000. It was later standardized as the System Reference Document (SRD) under the Open Game License (OGL), allowing third-party publishers to produce compatible material. The name refers to the system’s core mechanic, which uses a 20-sided die (d20) for most task resolution.

Gameplay centers on characters with ability scores, skills, saving throws, hit points, and a progression path of classes and levels. Most checks, including attacks, are resolved by rolling a d20, adding appropriate modifiers, and comparing the result to a target number such as a difficulty class (DC) or armor class (AC). The system emphasizes numerical bonuses, feats, and skill diversification, with enhancements through equipment and magical effects.

Key mechanics include attack rolls versus AC to determine hits, saving throws to resist effects, and a natural 20 or 1 often representing critical success or failure depending on the rule variant. Proficiency bonuses and often a tiered system of feats provide customization and specialization. The SRD version of the system enabled a wide ecosystem of compatible materials and settings beyond the original D&D products.

The d20 System’s open licensing approach significantly influenced RPG publishing, enabling numerous third-party and licensed games, such as d20 Modern and various setting books, as well as a broad array of compatible adventures and rule supplements. The framework remains a reference point for discussions of open game systems and the evolution of modular, rules-based role-playing play.