Question: fun things to do for a 21st birthday?
Answer: House Party. Gather up a bunch of your friends, and throw a (responsible) house party to celebrate your big day! ... 
Hotel Party. This should be for your close friends only. ... 
Casino. ... 
Clubbing. ... 
Bar Hopping. ... 
Paint Wine Glasses. ... 
Trip with Friends. ... 
21 Selfie Challenge.