In JJS, open the server settings and turn Friendly Fire off. That stops teammates from damaging each other, and if you want team visibility too, you can also enable Team Icons.

Quick steps

  1. Go to your server or private server settings.
  2. Find Friendly Fire.
  3. Switch it to Off.
  4. Optionally turn on Team Icons so players can tell who is on which side.

What this affects

  • Players on the same team won’t be able to hit each other.
  • This is the usual fix if teammates are still attacking each other.
  • If you’re using NPCs or team blocks, they may also need to be placed on the correct team for the setting to work as expected.

Common setup

A lot of JJS tutorials pair team blocks with Friendly Fire off , then use spawn points or teleport blocks so each team stays in its own area.

Friendly Fire: Toggles the ability for teammates to hit each other.[8]
TL;DR: **Server settings → Friendly Fire → Off**.