here's another variant rule for those wishing to include resistance fighters;
the idea is that each time you invade another player's planet, that some of its population will still feel connected to its former faction and resist the invasion, possibly liberating the planet on their own and rejoin their faction.
-you should provide rebel tokens specific for each faction.
-each time a rival invades one of your planets, you put 2 rebel tokens on it
-as long as there are any rebel tokens, during each maintenance phase you add 1d3 rebel tokens, once there are no rebel tokens left the planet's population has accepted the new rulers.
-the controller of the planet can use a command in his turn to try to eliminate rebels; perform a single round of planetary invasion, each hit obtained removes a rebel token, both ships in orbit and nodes on the planet participate, while the rebels defend.
-the rebels roll 1 die in planetary invasions per each full set of 3 rebel tokens, rebels and the opponent always hit on 5,6 regardless of weapons/shields, rebels can only target nodes on the planet
-the rebel's controller can use a command in his turn to start an insurrection, which is performed as a planetary invasion, this time there is no combat round limit so either the rebels win or the invaders win, so it must done at the right time to succeed.
-if ships of the rebel's faction invade the planet, then the rebels will aid as well
-once a planet is liberated (more rebel hits than there are nodes) or if all nodes are destroyed, remove all rebel tokens and place a control node of their faction. if there are no surviving rebel tokens the planet is considered razed instead.