how to change the size of a window?

[jdwagner888]

I know you can adjust the size of a window on OSX by dragging the little box in the bottom right of the screen.

I just downloaded portal 2 and wish to make the window a bit smaller on it.
unfortunately everytime i open it it extends its window down below my dock where i cannot get to the bottom right to bring it smaller.

is there a way around this?

 

[Alaerian]

Change the resolution from within the game.

 

[jdwagner888]

thx! helps alot!