@The_Picard_Maneuver against 1. e4 you can do Alekhine's defence, and if they do 2. e5 that is fun, and if they stay away you can just move to King's Indian or Pirc.
At my low level it's also a good way to dissuade the scholar's mate entusiasts out there.
Thanks, bookmarking this! I know I've seen it show up on the info block to the right of the board while playing before, so I bet this will feel familiar, but I can't remember if it's been my opponents or me (accidentally) doing it.