However, Valve also says that it's already stopped region locking games in the EEA in 2015, except where required by law to prohibit sales of certain games in specific regions.

Steam, one of the sole bastions of sanity when it comes to digital games distribution, has enabled region locking on games. This means if you buy a game in one territory, you can no longer use it ...

Valve has responded to the Commission's concerns, saying in a press release that it had already turned off region locks on these game keys within the European Economic Era in 2015, "unless those ...

The European Commission is accusing Valve of region locking in its single-market, which the EU does not permit. But Valve said it ended the practice.

This means if you buy a game in one territory, you can no longer use it in another territory -- much like DVD region locking (but more effective, as Steam's region locking hasn't been cracked).