playgroundrule

2. An informal, widely accepted guideline for behavior in a shared play area.

Sharing the slide is an unwritten playground rule everyone follows.

3. A rule enforced by a school or park to keep children safe during play.

The new playground rule says kids must wear shoes on the play structure.

4. A basic principle of fair conduct that people apply in any group setting.

In this office, taking turns in meetings is just a playground rule we all respect.