# Contracts

Rules every device checks the same way, so a result is a fact and not one app’s say-so. Like a smart contract, without a blockchain.

## What it enables

- Games nobody can cheat at: only legal moves count
- Mutual credit, where nobody can spend the same balance twice
- Proposals that pass only with enough votes
- A hall of fame that needs five different people’s 🙂
- Chores that count as done once two people nod, with computed fields

## In this section

- [Contracts](https://minca.dev/contracts/contracts.md): A contract says when a version of a record counts. Use one when every app must agree on something no single writer can be trusted with: a proposal that passes only with enough votes, a move that…
- [Computed fields](https://minca.dev/contracts/computed.md): A computed field is a value every app works out from the records it holds, instead of one somebody writes. Use one for counts, tallies and flags that follow from other records, like "a to-do is…