How to play the triangle peg game
The rules take a minute to learn. Leaving a single peg takes rather longer. Here's everything you need, with diagrams.
The board
The board is a triangle with 15 holes in five rows: one hole at the top, then two, three, four and five. On this site the holes are numbered 1 to 15, row by row from the top, and a jump is written as the hole it starts from and the hole it lands in. So 4-1 means the peg in hole 4 jumps to hole 1.
Setting up
Fill every hole with a peg, then take one out. Which one is up to you, and it matters more than you might expect: some starting holes are much harder than others (see the strategy guide). In the game, you start by clicking the peg you want to remove, or by choosing Random start.
Jumping
A move is always a jump:
- A peg jumps over one neighbouring peg, in a straight line, into the empty hole directly beyond it.
- Lines run along the rows and along both diagonals, so a peg can jump in up to six directions.
- The peg that was jumped over is removed from the board.
- Only one jump is made per move. There's no chaining like in checkers; each jump is its own move.
- A peg can't jump over an empty hole, over two pegs at once, or off the board.
Every jump removes exactly one peg, so a game that starts with 14 pegs can last at most 13 jumps, and a perfect game is exactly 13 jumps long.
The end of the game
The game ends when no peg has a jump. There's no passing and nothing else to do, so whatever is left on the board is your score. Pegs that end up spread out, with no two side by side, can never move again.
Scoring
A game is judged by how many pegs are left at the end. Tricky Triangle rates a finish like this:
| Pegs left | Rating |
|---|---|
| 1 | Genius! The puzzle is solved. |
| 2 | Very clever: one jump from perfect. |
| 3 | Not bad: you're getting the hang of it. |
| 4 or more | Keep trying. |
For an extra challenge, try to finish with the last peg standing in the hole you started from. It can be done from 12 of the 15 holes. The solutions page shows how.
Using the game
- Start: click any peg to remove it, or choose Random start.
- Move: click a peg, then the highlighted hole it can jump to. Click the peg again, or press Esc, to pick a different one. The board also works with the keyboard: Tab to a hole and press Enter.
- Undo takes back the last jump, as many times as you like.
- Restart plays again from the same starting hole. New start lets you pick another.
- Hint selects a peg and marks a jump that still leads to the best possible finish from where you are.
- Helpers outline the pegs that can jump and tell you whether one peg is still possible. Turn them off for a purer challenge.
- Your record counts your games and fills in a small triangle with every starting hole you've solved from. It's kept in this browser only.
Ready? Play a game.