|The overall brightness can be adjusted brighter on the monitor itself, unless it's no longer capable of that, in it's OSD settings. You press a button to pop up a menu and use buttons to select things to adjust and adjust them. |
The brightness in a game can usually be adjusted in settings in the game itself.
Games are a separate thing. Adjust the brightness of the monitor so everything other than games are bright enough to make out detail.
Adjust the games individually if that's not enough for them, if they have the setting for that. The brightness will return to the overall less bright setting when you exit the game.
If you set the monitior brightness to suit the games, it will probably be too bright for some things otherwise, and the lower you can set the monitor overall brightness, the longer time your display will produce a good enough display.