01 / Before the invite
Remove the account friction first
- Link a Microsoft account on every platform. Cross-play and cross-progression use that account. Steam and PlayStation also need an internet connection for the initial account link.
- Add cross-platform players by Xbox Gamertag. A Steam or PlayStation username alone is not enough for the cross-platform list.
- Set linked Xbox accounts to appear online. Official support warns that Steam or PlayStation invites can fail when the linked Xbox account is offline.
- Keep everyone on the main menu for the invite. PlayStation and Steam players must be there to receive in-game cross-platform invites.
02 / Choose the host
Host for progress, not seniority
The Fireteam Leader determines which missions and Skulls are available. A leader who is earlier in the campaign can restrict a more advanced player. A leader who is further ahead may expose later missions to the group.
Best defaultUse the player with the most useful unlocked route and the most stable connection.
AvoidSwitching hosts mid-session without checking the new leader's mission and Skull unlocks.
03 / What survives
Know the difference between unlocks and position
Synced across platforms
- Mission and Rally Point unlocks
- Skulls
- Terminals
- Achievements
Not synced across platforms
- Mid-mission checkpoints
- Exact player position
Co-op permanently grants shared mission, Rally Point, Skull, and Terminal unlocks to the fireteam as they play. It does not mean every earlier mission is automatically filled in: completing mission 5 grants mission 5, not missions 1 through 4.
04 / If joining fails
Use this short failure order
- Confirm the friend request was accepted on the Xbox network.
- Close and reopen the in-game friends menu, then restart if needed.
- Confirm multiplayer, cross-platform multiplayer, and online interactions are allowed in account privacy.
- Check that the in-game Cross-play toggle is on.
- Make sure the fireteam is not full and the leader's lobby is not restricted.