Practical guide

D20 checks, attributes, and progression

How d20 checks, difficulty, advantage, consequences, levels, and abilities work in an AI RPG.

· Beyond The Verge Editorial

Short answer

An uncertain action becomes a server-owned check: d20, an attribute, modifiers, and difficulty produce one of a bounded set of outcomes. Progression and abilities are versioned and have provenance, so narration cannot simply award a level.

What to do

  1. The engine first classifies an action as automatic, impossible, or uncertain.
  2. The interface shows the roll, difficulty, and applicable modifiers.
  3. The result changes state only after validation and atomic persistence.

Practical scenario

A hero leaps across a collapsing bridge. A strong result may be clean success, a middling result success with a cost, and failure a confirmed consequence rather than arbitrary death.

Limitations

  • The system does not copy licensed tabletop classes or spells.
  • A player declaration alone cannot grant a level, ability, or item.

Common question

Does every action require a roll?

No. Obvious actions resolve automatically, impossible actions are rejected, and d20 is used when the outcome is genuinely uncertain.

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