Tic-tac-toe is boring. Unless the people playing are completely confused it always ends in a draw.

Gobblet on the other hand is quite interesting. In this game the basic rules are the same as in Tic-tac-toe; once you get 3 in a row you win. Each player has 2 sets of 3 ghosts (large, medium, small). The twist is that larger ghosts are allowed to be placed on top of smaller ghosts, meaning you have to be strategic with what sizes you use.

In other words, the game is extremely simple, but it's quite fun!

The bare minimimum to play is:

• 2 sets of ghosts for each player, meaning 2 large, 2 medium and 2 small
• The lid

Ghosts

The ghosts are in fact 3 ghosts. They are easy to print, no supports should be needed. Trim any elephants foot, since it might cause the ghosts to get stuck in each others if pushed (not a big deal)

Lid

The lid is also the board. It should be printed flat and I suggest you have enough top/bottom layers to not need any infill at all, since that often messes with flat surfaces.

Box

You don't really need the box to play the game, but I find it quite nice to have somewhere to store the pieces. It might be good to use supports for the lock-hole at least, since having it a bit deformed might make insertion of the lock harder.. that said, I didn't.
You might ask, why is there place for 6 sets of ghosts when only 4 are needed? Well... the box had the space for it... and I printed a bonus set when testing... you could fill it with candy and give to the winner!

Lock

You don't really need the lock even if you print the box, but I think it's a nice detail. That said, I had to use pliers to get it in place; I therefore added a lock with a less tight fit.