Originally posted by Hamstersex:

Yep, you can do this:

Can Idle Master be used to pad my playtime of a particular game?
The steam-idle.exe application that's included with Idle Master can be given a command line argument of the appid of the game you'd like to idle. For example, if you'd like to idle Team Fortress 2 for playtime, you can simply run "steam-idle.exe 440" from a command prompt. There is no user interface for this, it must be done through the command line.

http://psteamcommunity.yuanyoumao.com/groups/idlemastery/discussions/0/615085406651320102/

Where would i put the command? i have no knowledge of this kinda stuff

Is there anyway to use idle master to idle for hours. I dont have any trading cards left i just wanna idle a couple of my games to bring up the hours.