RIVEN Part 1 — The Core Rules
22 April 2026
I'm building a game.
Not a modification of someone else's system. Not a one-shot supplement. A full solo narrative wargame — with campaign rules, dungeon crawls, rollable tables for everything, and the same engine running two settings: low-magic fantasy and hard sci-fi.
I'm calling it RIVEN. And I'm building it one part at a time, publishing each module as it's done.
Part 1 is the core rules. Everything else builds on top of these.
Why RIVEN?
I play solo. No regular group, not enough evenings, too much to organise. But I want the tactical crunch of a wargame and the narrative richness of an RPG — in 30–45 minutes, with 1–3 models, no GM required.
The closest games to what I want are Song of Blades and Heroes (a brilliant point-buy wargame with the most elegant activation system in the hobby) and Ironsworn (a solo RPG with one of the best oracle toolboxes ever designed). RIVEN borrows heavily from both.
The Two-Dice Engine
RIVEN runs on two dice systems. They do different things and never conflict.
1. Activation (d6 pool)
Before activating a model, you choose to roll 1, 2, or 3 d6 dice. Each die is checked independently against the model's Mettle threshold (2+, 3+, or 4+ depending on the model's quality).
- Roll ≥ Mettle: success
- Roll < Mettle: failure
Count your successes:
| Result | Actions | What happens | |---|---|---| | 0 successes | 0 | Turn passes to the opponent immediately | | 1 success + failures | 1 | One action; turn passes | | 1 success, no failures | 1 | One action; activate another model or pass | | 2 successes | 2 | Two actions; continue | | 3 successes | 3 | Three actions; continue |
This is the heart of the game. Rolling 3 dice might give you 3 actions — or it might hand the turn straight to your enemy. Every activation is a decision.
2. Tests (2d6 + attribute)
When something uncertain happens — an attack, a skill check, a power use — roll 2d6 + the relevant attribute against a target number.
| Roll | Result | |---|---| | 2–5 | Miss — fail with a complication | | 6–8 | Partial — success with a cost | | 9–11 | Hit — clean success | | 12+ | Critical — exceptional outcome + 1 Momentum token |
The partial band (6–8) covers roughly 42% of all rolls. That's where narrative games live — you got what you wanted, but.
The Four Attributes
Every model has four attributes rated 1–5, plus a Mettle tier:
- Might — melee, brute force
- Agility — ranged, speed, evasion
- Wit — cunning, perception, traps, morale
- Power — Arcana (fantasy) or Tech (sci-fi) — same mechanic, different flavour
Starting heroes: 9 points to distribute, no stat above 4 at creation.
Mettle is not an attribute — it's an assigned tier (2+, 3+, or 4+) that determines how reliably a model activates. Elite models are expensive in point-buy. Rookies are cheap but risky to roll 3 dice with.
Download the Core Rules
The full formatted core rules document is free to download. It includes:
- Complete activation and test mechanics
- All four attributes and Mettle tiers explained
- Full combat rules (melee, ranged, going Down)
- Morale-as-movement (stolen from Song of Blades)
- Momentum and Strain systems
- Quick reference card
Download RIVEN Core Rules v0.1 (HTML)
What's Coming
Next: The Oracle — the yes/no/yes-but tool that makes solo play possible without a GM.
The build plan, part by part (it's done when it's done, no schedule):
- Part 1: Core loop — rules, first fights (this post)
- Part 2: The Oracle — solo play toolkit
- Part 3: Solo toolbox — scene generator, mission generator, escalation
- Part 4: Campaign rules — 3-act structure, XP, injuries, advancement
- Part 5: The dungeon module — procedural crawls, wandering monsters, treasure
- Part 6: Full compiled PDF release
Every module is free. Every one is standalone — you can pick up any piece and use it without the others.
If you try it, let me know how it goes.