Triplexity

Triplexity ... a game of complex simplicity, otherwise known as vertical tic-tac-toe.

The goal: to be the first to place your 3 colour pieces in a single stack or on the top of each of 3 stacks.

Players take turns placing their pieces, one at a time, in 3 positions: left, centre, right - stack max. 3 pieces high.
When all 6 pieces have been placed, the game continues with players moving any colour piece – yes, even the opponent's.
The piece last moved may not be returned to its previous position on the next turn.

Triplexity (Advanced) is played, in the same way, for points.
Play an agreed number of rounds or to a target score.

The pieces, numbered with pips similar to opposite sides of a regular die, are placed either-way-up and are always inverted when moved.
Tally the number of pips face-up on the 3 winning pieces to determine the score.

FYI – the pieces are a pair of thrice-sliced dice and the game can be brain-bending (mind-numbing)!