A phrase mentioned by Admiral Ackbar in "Return of the Jedi", in which states the obvious: The Rebel fleet fell under a trap set up by the Imperial Navy. Now used in several message boards as a multi-purpose phrase
Admiral Ackbar: "Take evasive action. Green Group, stay close to holding sector MD-7."
Crewman: "Admiral, we have enemy ships in sector 47!"
Ackbar: "It's a trap!"
used when something could potentially have a bad outcome. This thing must be obviously and/or previously discussed as almost exactly what the above definition states, if not, exactly.
person 1: don't go in this room
person 2: (to person 3) what happens when we DO go in?
person 3: idk, but I think there's somethingdangerous in there...
person 2: IT'S A TRAP!!!
Reference to a joke which is so unfunny, it belongs in It's A Trap, which is the third Star Wars parody made by the Creators of Family Guy. It is a terrible film and hence why said joke belongs there.
Will: Yo momma so fat she had a heart valve replacement!
Simon: It's a Trap
Ryan: Yo momma so poor she homeless!
Simon: That definitely belongs in It's a Trap
In Starwars: Return of the Jedi, during the assault on the second Deathstar, the Evil Emperor lures the Rebel forces into a trap.
The Master of the Obvious, and Admiral of the Rebel Fleet, Admiral Ackbar exclaims "IT'S A TRAP!", after one of his subordinates says "Enemy Ships in Sector 47!"
This is fundamentally the greatest Star Wars line, and one liner ever.