Stars Without Number vs Worlds Without Number
Compare Stars Without Number and Worlds Without Number side by side. See differences in complexity, dice, genre, and more.
| Stars Without Number | Worlds Without Number | |
|---|---|---|
| Genre | Sci-Fi | Fantasy |
| Tags | Sandbox, Exploration, Low-Prep, Faction Play, Tactical, Ascending AC, Vancian Casting | Sandbox, Exploration, Faction Play, Strong GM Support, Gritty, Classic Fantasy, Random Tables, Hexcrawl, Low-Prep, Domain Management |
| Core Mechanic | 2d6 + skill + attribute ≥ target for skills; d20 + modifiers for combat. OSR-inspired. | Skill checks roll 2d6 plus the relevant skill level and attribute modifier against a difficulty. Attacks roll d20 plus base attack bonus, combat skill, and attribute modifier against the target's Armor Class. A missed melee attack can still inflict Shock damage when the target's AC is low enough. |
| Dice | 2d6 / d20 | 2d6 / d20 |
| Complexity | Medium | Medium |
| Availability | Free core rules | Free core rules |
| Runnability | 5 of 5 book tools | 5 of 5 book tools |
| License | Proprietary | CC0 1.0 Universal (SRD 1.0); proprietary core books |
| Third-Party Publishing | Not yet researched | Commercial publishing allowed — Worlds Without Number System Reference Document (SRD 1.0) under CC0 1.0 Universal |
| Summary only, not legal advice. Check current terms before publishing. | ||
| Publisher | Sine Nomine Publishing | Sine Nomine Publishing |
| Year | 2017 | 2021 |
| Languages | English | English |
| Best For | Sandbox sci-fi campaigns with comprehensive GM tools for faction turns, sector generation, and adventure creation. | Groups who want an open fantasy sandbox where their own goals drive play. Faction turns and campaign-building tools keep the world moving between sessions. |
| Highlights | Free version is generous, comprehensive sandbox tools, faction system | The campaign chapter turns worldbuilding into procedures, with tags and tables that keep sandbox preparation to one session ahead. Faction turns let rival powers act between sessions, so the setting changes even when the players are elsewhere. Shock damage keeps melee misses meaningful and makes armor and shields matter in close combat. |
| Considerations | OSR combat can feel flat compared to modern tactical systems, B/X heritage means limited mechanical support for social or narrative play | Combat resolution is deliberately simple, with positioning and Shock carrying most of the tactical weight. The rules assume a sandbox campaign and offer little structure for pre-planned story arcs. Social conflict is handled by skill checks and GM judgment rather than a dedicated subsystem. |