Advertising

To reveal the secret contents of the Weasley twins' infamous "Marauder's Map," a wizard had to tap it with a wand and say, "I solemnly swear that I am up to no good."

And say "mischief managed" to put it away.
And say "mischief managed" to put it away.

Revealing the words on this Reddit user's "Maruader's Map" tattoo is a lot easier. All you need is a black light.

You don't get a map, but you hopefully get a discount at the Harry Potter theme park.
You don't get a map, but you hopefully get a discount at the Harry Potter theme park.