CPU time
Game play was also affected by the Plato system's context switching CPU scheduling algorithm. Plato attempted fair allocation of the limited CPU resources available by calculating for each user the ratio of the total CPU time used during a session divided by the total duration of the session. The system would grant extra CPU time to sessions with lower CPU time/session duration ratios at the expense of sessions with higher CPU time/session duration ratios. "Empire" players would obtain more CPU for game play by logging in hours before commencing game play and leaving the session idle, thereby accumulating a very low CPU used/session duration ratio that would ensure high CPU allocation to the player during game play. Players who did not engage in this practice were burdened with poor game responsiveness due to relative lack of CPU.