Planet Busters (1982)

Originally published in Dragon Magazine, issue #64.

From the Introduction: It is the far distant future. The planets around the sun have been tamed and colonized by humans. Unfortunately, the interplanetary government has grown corrupt and feeble. Power groups are marshaling their forces in efforts to gain control of the worlds, and the warships with which to hold them. Players are the leaders of these factions... all seeking to bring the most planets under their control. It will be a desperate struggle, and no one knows who will win!