The Official Roommate Scorecard.
The Official Roommate Scorecard	
Takes out the trash	+3
Cleans the kitchen	+5
Pretends to clean the kitchen but really just wipes the dirt around with your only clean sponge	-2
Buys new sponges	+4
Leaves their weed stems on the coffee table	-1
Lets you smoke their weed	+5
Buys toilet paper