look up any word, like dirty sanchez:
 
1.
When you completely fluke out and do something perfectly through dumb luck. The term is derived from the roll playing game Dungeons & Dragons in which rolling 20 on a 20 sided dice guarantees success at whatever your attempting.
"Dude, did you see Jimmy get hit by that car? He flipped over the hood and landed on his feet!"
"Shit, way to roll a twenty on his acrobatics."
by Lvl20warlock November 22, 2007
 
2.
rolling an entire 20 bag of weed in one joint (UK)
"can i skin up with ur weed". "yeah man roll a twenty i got another bag here"
by Lee Parker April 13, 2008