> Markdown twin of https://adna.network/glossary/glossary-collision-prevention/
> Index: https://adna.network/llms.txt · Full corpus: https://adna.network/llms-full.txt
> State is a build-time snapshot generated 2026-08-30 (UTC); nothing here is live.

# Collision Prevention — aDNA Glossary

## Plain-Language Definition

Collision prevention is how aDNA protects files from being accidentally overwritten when multiple agents (or humans) work in the same project. It uses three tiers: basic rules everyone follows (like "read before you write"), extra precautions for synced environments, and full coordination protocols for concurrent multi-agent work.

## Technical Definition

A tiered system protecting against data loss from concurrent modifications. Tier 1 (Universal, MUST): [frontmatter](/glossary/glossary-frontmatter) attribution on every edit, read-before-write, new-file safety. Tier 2 (Sync Environments, SHOULD): file safety tiers, archive-don't-rename, one shared config at a time. Tier 3 (Multi-Agent, SHOULD): [coordination notes](/glossary/glossary-coordination-note), session scope declarations, update-field conflict checks. Projects adopt tiers based on their operational complexity. (aDNA Standard §13.1-§13.4)

## Usage Examples

- This vault follows Tier 1 collision prevention: every file edit updates `last_edited_by` and `updated` in frontmatter — including this glossary entry you are reading now.
- The escalation from Tier 1 → 3 mirrors the vault's own growth: a solo project needs only Tier 1; a team project with concurrent agents adds Tier 3.

## See Also

- [Frontmatter](/glossary/glossary-frontmatter)
- [Coordination Note](/glossary/glossary-coordination-note)
- [Session](/glossary/glossary-session)