Eclipse: Second Dawn for the Galaxy – Expanded Galaxy

No. Allied ships do not pin each other, though they are treated collectively when opponents determine pinning (p. 5).

Alliances are not used in 2- or 3-player games, and a player can belong to only one alliance. In 4–5-player games, an alliance can have up to two players; with 6 or more, it can have up to three (p. 5).

Leaving does not give you the Traitor Card and does not affect your Diplomatic Relations, but your former allies’ ships or control in a sector where you have ships can make your presence an Act of Aggression. You cannot rejoin an alliance you left (p. 5).

Faceup Alliance Tiles are worth 2 VP and Betrayer-side-up tiles are worth −3 VP. Add the allies’ VP, divide by the number of allies (rounding down), and the alliance wins together if that score beats all opponents (p. 6).

Each marker holder takes one action, reaction, or pass, then immediately passes their marker clockwise; one player cannot hold both markers at once. Only the Primary marker holder may take the Research action (p. 4).