## Rock-Paper-Scissors Without the Luck

As I’ve mentioned before (click here for his “Duke and Pawn” game, or click here for a more game-theoretical type of game), my son Adam enjoys designing games. Here’s a game he designed, with very simple rules but complex play, on the theme of Rock-Paper-Scissors.

1. The two players are White and Black, and they each have three pieces, a Rock, a Paper, and a Scissors, that they set up on a 6 by 6 board as shown below.

2. White moves first, and then the players alternate.

3. Normally, a player moves a single one of his pieces one square orthogonally (up or down or right or left) on each move. You may not place a second piece on the same square except to capture. (So for example, on the first move, White’s legal moves are to move his Paper up or to the left, or his Scissors up or to the left.)

4. Rocks can capture Scissors, Scissors can capture Papers, and Papers can capture Rocks (of the opposite color in each case) but no other captures are possible. A piece can be moved a second time on the same move if and only if it enables it to make a capture that move (e.g. if a Paper is diagonally below and to the right from an opposing Rock, it could move up and then move left in order to capture the Rock.)

5. The object of the game is to move one of your pieces to the square where the opposing Rock is placed at the beginning of the game. If you do so, you instantly win the game.

6. You may never repeat a position.

7. You must move each turn. If you have no moves, you lose.

The game has no draws. One important and non-obvious point of strategy: if you exchange your Rock for your opponent’s Scissors, you will have an important material advantage, because your Paper can safely rampage without worrying about any of his pieces, while his Rock still has to worry about your Paper, and his Paper still has to worry about your Scissors.

It might appear that the first player has a significant advantage, but our games haven’t worked out that way at all. By the way, we use Chess pieces for the pieces; rooks for rocks, pawns for papers, and bishops for scissors.

I like the irony that ordinary Rock-Paper-Scissors is a game of complete chance and Adam’s version has no chance. Have fun!

(EDIT: This game now has a name; it’s called “Cyclotron.”)

### 12 Responses to “Rock-Paper-Scissors Without the Luck”

1. Graham Walker Says:

I like the game your son designed very novel.

You are dead wrong about your ‘irony” comment though. You can certainly debate how much strategy is in the game but there is no question that it is not a game of chance.

Here is an article you should find worth reading: Is There Strategy in Rock Paper Scissors?: The Definitive Guide

2. Sproaticus Says:

I love it. Very simple, very thought-provoking.

I’d love to see a variant using higher orders of RPS, like the 15-element version at http://www.umop.com/rps15.htm

3. Eric Says:

Hi, I like this game. Does it have a name? I assume “Rock-Paper-Scissors Without the Luck” is just the title of the article and not the name of the game?

1. Just to clarify: You can capture the appropriate piece if it is 1 or 2 squares away in a straight line or on an “adjacent” diagonal, correct?

2. Moves that would lead to a repeated position are forbidden… so, combined with the rule that you must move or lose, if all a player’s moves lead to repeated positions, that player has effectively lost. Correct?

Eric

4. pernishus Says:

Personally, I feel this game bears a strong resemblance to “Einstein doesn’t play dice.” You can see the game on http://www.littlegolem.net under Einstein wurfelt nicht or something like that. While this game is different, I wouldn’t call it a novel design. But hey, everyone has to start somewhere.

5. Jonathan Yedidia Says:

Eric, I suppose you can call it “the Rock-Paper-Scissors boardgame.” I’ll need to ask Adam if he has some better name.

About the rules, yes you can capture the appropriate piece if it is 1 or 2 squares away in a straight line or an adjacent diagonal. And yes, if all your moves lead to repeated positions, you lose.

Pernishus, I don’t think it resembles “Einstein doesn’t play dice.” The most important difference is that there is no luck in the Rock-Paper-Scissors game, and you roll a die to decide which piece to move in “Einstein doesn’t play dice.” But the pieces also move differently, capture differently, and the strategy is completely different. I doubt Adam was aware of the “Einstein doesn’t play dice” game, and I also doubt he’d like it much, because he dislikes games that have a heavy luck component.

6. Eric Says:

Thanks for the clarification, Jonathan! I’m terrible at naming things, so I can more than understand the desire to call it by a descriptive like “the Rock-Paper-Scissors boardgame”! : )

7. Jonathan Yedidia Says:

Adam likes the name “Cyclotron” (originally suggested by his younger brother Zachary.)

For those of you who haven’t noticed, Eric has a great web-site called Vying Games where you can play lots of interesting strategy games, against bots or humans.

8. Eric Says:

Thanks for the plug, Jonathan. : )

9. pernishus Says:

Jonathan,

This game is certainly different from Einstein doesn’t play dice, but I’d call it a variant at best. As far as I can tell, pieces move and capture exactly the same(move one space, move over another piece to capture) and the end goal (capture all enemy pieces or move one of your pieces to the last space) is exactly the same. If I took parcheesi, and said you could pick from a list of die rolls, it would be a different game, but a variant none-the-less. If I further limited how you could capture pieces, it would still be a variant. It may be unfortunate that someone else had the bulk of the idea first, and published it, and won awards for it, but that’s how it goes. Same board, same initial setup, same end goal, same basic movement makes this game a variant of Einstein doesn’t play dice. Perhaps an interesting variant, but not a novel game design. Eric, please continue to encourage your son in his design efforts; I’m not trying to belittle his accomplishments, just clarify their scope. Also, their are some excellent game designer blogs you might want to check out.

10. Jonathan Yedidia Says:

Pernishus,
I have no idea why you feel it’s important to call Cyclotron a variant of Einstein Doesn’t Play Dice (EDPD). There are many games that involve moving pieces on a board. If you want to, you can say they’re all variants of each other.

Here is a list of the differences between Cyclotron and EDPD, so those who care can judge for themselves:

1. In EDPD, you roll a die to choose which piece to move. In Cyclotron you choose freely.
2. In EDPD, you have 6 pieces numbered 1-6. In Cyclotron you have three pieces: a rock, paper, and scissors.
3. In EDPD, you move up or left or diagonally, always towards your goal. In Cyclotron you move up or down or left or right, and may move your pieces away from the goal but not diagonally.
4. In EDPD, any piece may capture any other piece, including your own pieces. In Cyclotron, a piece may only capture an opponent’s piece, and only if it is a rock capturing scissors, scissors capturing paper, or paper capturing rock.
5. In EDPD, there is no difference between moves that capture and moves that don’t. In Cyclotron, you may move a piece a second time if and only if it results in a capture.
6. EDPD is played with a 5×5 board, with 6 pieces on each side. Cyclotron is played with a 6×6 board with 3 pieces on each side, so the board is considerably less crowded.
7. In Cyclotron you may not repeat a position, and if you can’t move you lose. EDPD doesn’t have these rules.

As far as strategy goes, Cyclotron is a complete-information no-luck game so naturally the strategy is very different from a dice game like EDPD, where the strategy is about maximizing your odds.

11. pernishus Says:

Jonathan,
I’m sorry that you cannot see that the differences are not significant. The strategy that you employ in each game is of course different, but the game mechanisms are essentially the same. Can we at least agree that my description of parcheesi where players choose from a list of dice rolls, have limited capturing abilities, can move backwards, and play on a slightly longer track would be a variant of parcheesi? Furthermore, take a look at chess variants. There are thousands on chessvariants.net. Pretty much anything that uses some chess pieces and a chess board is classified as a variant. Do you see the similarities to our discussion here? Btw, in an earlier comment I got confused over whose son’s design we were talking about and I incorrectly referred to Eric’s son (which he may not even have) by mistake.

12. Jonathan Yedidia Says:

Pernishus,
I think we’ll need to agree that we disagree and leave it at that.