couldn't act/argue/fight way out of a paper bag

couldn't [act/argue/fight] your way out of a paper bag (humorous)

if someone couldn't act, argue, fight etc. their way out of a paper bag, they act, argue, fight etc. very badly. It's no good asking Jim to protect you - he couldn't fight his way out of a paper bag.

See also: act, argue, bag, couldn't, fight, paper, way