GCL

Screeps has two different kinds of levels, namely the Global Controller Level and the Room Controller Level.

Global Control

The Global Controller Level is the main indicator of progression in the game. Much like Room Controller Levels, it is advanced by spending energy on upgrading the Room Controllers. The Global Controller Level is however an accumulation of the total amount of energy that have been spent on upgrading room controllers, across any player owned rooms.

Players start at GCL 1, and can control a maximum of 1 room. Each additional Global Controller Level gives the player the ability of owning one new room. Apart from being able to control more rooms, players with a Subscription also gain an additional 10 CPU for each Global Controller Level.

Progression

It is widely agreed upon that advancement through the first controller level is the most time-consuming. As players progress past this point, progression speeds up relative to the amount of energy spent on upgrading across all of the players rooms. ^{Nonspecific: Is there a point where this stops being true?}