In Planet Defenders, players pay batteries to control the three defenders, moving them among the planets and collecting energies. Players can enhance their actions by spending energies or batteries to upgrade their technology. They earn the research points (RP) by catching the disposed robots in outer space and by collecting technology cards.
When robots from two different piles are depleted, complete the current round so that all players have an equal number of turns. The player with the highest RP wins.