Como dizer "É tudo combinado (marmelada)" em inglês

For prank purposes, I believe the best ones would be:
Setup:
"I can't believe you fell for it! The fake spider on your desk was a setup all along!
Rigged:
"The office chair was rigged with a whoopee cushion to make a funny sound when someone sat on it."
A Sham:
"The 'alien invasion' video we saw was a sham created by our classmates for April Fools' Day."
A Con:
"The 'free pizza for everyone' flyer was a con by our colleagues to get us to come to the meeting early."
A Ploy:
"The 'broken elevator' sign was a ploy to get us to take the stairs, where a surprise party was waiting."

You could also go with:
"The scene was staged."
"It was set up beforehand."
"It was orchestrated."
"The situation was pre-planned."
"It was a scripted scenario."
"It was a pre-arranged scene."

Hope I've helped