Three Men's Morris
Three pieces each. Once they're down, slide them.
X's turn
How to play
Three Men's Morris is played on nine points joined by sixteen lines: the twelve short ones between neighbours across and down, and four that run from the centre out to the corners. That makes the centre the busiest point on the board. It's joined to all eight others, and every other point is joined to three. Each player has three pieces.
First you take turns putting your pieces down on empty points, one at a time. Once all six are down, you move instead. On your turn, slide one of your pieces along a line to the next point, as long as nothing is on it. There's no jumping or flying anywhere; every move is one step. Get your three pieces in a row and you win, and that counts while you're still placing them, too.
A player with nowhere to move loses, although on this board it never actually decides a game. Any position that boxes you in already has three in a row for somebody, so the game ended a move earlier. What can happen is a loop. If the same position comes up a third time, the game is a draw. So is a game that runs fifty-four moves after the last piece goes down, which is as much history as a shareable link can hold.
The rules for this game vary. Some boards leave out the diagonals, and some rules let a player with three pieces move to any empty point. This board has the diagonals, and nobody flies.