RPS.

September 11, 2002 9:00 AM

RPS. Not some new government organization, nor a new tech term. I am speaking of the age old decision maker, Rock-Paper-Scissors. Who knows how many important decisions in the course of history have been decided by this method. A little bit of fun here on such a somber day, just don't let your co-workers catch you practicing against the computer.
posted by Addiction (18 comments total)

I taught my kids the Rock-Paper-Scissors-Spock-Lizard variant, and we find it much more enjoyable.

And here is the computer version.
posted by jazon at 9:30 AM on September 11, 2002

I was always partial to to "Eenie Meenie Meinie Moe," but with so many to pick from I'll have no problem making decisions for the rest of my life... now, which method do I want to use?

Eenie, meenie...
posted by furious-d at 9:39 AM on September 11, 2002

Lizards play Rock-Paper-Scissors.
posted by ALvard at 9:54 AM on September 11, 2002

Though the gambits and advanced play examples on the WorldRPS page are mostly in jest or are psychological tricks, there is some real mathematical strategy in the game other than pure randomness. I was shocked to learn that there was an RPS programming contest, with some bots dominating their opponents.

The FAQ for the contest states that a purely random player will place in the dead middle of the pack. A friend of mine entered the contest, and placed 29th out of 62, so he actually did worse than a purely random player. Just a little bit insulting!
posted by zsazsa at 10:47 AM on September 11, 2002

zsazsa, not to pick nits but if your friend finished 29th of 62 wasn't he actually two spots higher than mid-pack, which would be thirty-first?

Or is this that new math I keep hearing about?
posted by mr_crash_davis at 11:00 AM on September 11, 2002

Jazon: RPSSL is cute, but you can actually extend the game to any odd number of different plays greater than 1. Rock-Paper-Scissors-Spock-Lizard-Gun-Dinosaur-Cylinder-ThumbsUp anyone?

(1 beats 2, 3, 4, and 5; loses to 6, 7, 8, and 9. 2 beats 3, 4, 5, and 6; loses to 7, 8, 9, and 1. And so on around the circle. This doesn't work for even numbers because - well, take 4. 1 beats 2 beats 3 beats 4 beats 1, fine. But if I play 1 and you play 3, we're stuck. I can't beat you because that would make 1 a stronger play than 3 always. You can't beat me because that would mean 3 was always stronger than 1. Since the game is founded on every play being equally balanced...)
posted by wanderingmind at 11:28 AM on September 11, 2002

A.k.a. rochambeau, though I prefer Cartman's version (213K .wav).
posted by gottabefunky at 11:32 AM on September 11, 2002

Most ro-sham-bo enthusiasts are already aware of the handy online multiplayer version, but it would be a shame for it to go unmentioned in a thread such as this.

Also, our family has always used the "drill" as the wildcard play during unofficial contests, and recently the "eagle claw" (a la Peppermint Patty) has made appearances as well. Ro-sham-bo can solve the world's problems, as long as we can all give each other two-outta-three.
posted by majick at 12:21 PM on September 11, 2002

The Japanese play paper-scissor-rock (janken) to decide things all the time, super-fast while singing a little chant.

If you ever want a laugh, ask a Japanese to toss a coin. They can't.
posted by dydecker at 12:28 PM on September 11, 2002

I thought it was ro-sham-bo, because Rochambeau was commander of the French forces during the American revolution.

I don't think he went around kicking anyone in the balls, either.
posted by nyxxxx at 12:51 PM on September 11, 2002

We played the scissors-paper-rock-dynamite version. Dynamite (a single finger in the palm) beats everything.

My question: do you, yourself, call it:

a. scissors-paper-rock
b. rock-paper-scissors
c. paper-scissors-rock
d. paper-rock-scissors
e. scissors-rock-paper
f. rock-scissors-paper
posted by Mo Nickels at 12:58 PM on September 11, 2002

I don't know if there are any old Sega Master System owners out there, but in the game "Alex Kidd in Miracle World" you had to play janken to beat the end level bosses. It helped if you had gotten the special power to read the end guy's mind and see what he was picking. Except that they would change it at the last second. I tried playing a little while ago and I sucked. Hmm.
posted by hellinskira at 1:13 PM on September 11, 2002

It's "jan-ken-po" in Hawaii, obviously from the Japanese variant, but of course infused with the flavor of our distinctly mish-mash of cultures.

We even have a TV game show incorporating it.
posted by pzarquon at 1:16 PM on September 11, 2002

"...while singing a little chant."

That's why we've always called it ro-sham-bo: The chant used -- for the purpose of synchronizing the throw -- in multiple generations of my family was "Ro.... Sham.... BO!" with the throw made on "BO!". I imagine other folks count off "one, two, THREE!" or some such.

When I was little, it's because I thought "ro" meant "rock" in Tagalog (or possibly some other language), "sham" meant "scissor", and "bo" meant "paper." Having acquired not one word of comprehension of my mother tongue, I have yet to determine if this is actually the case but I certainly have my doubts.

Nearly everything was decided in my childhood by roshambo, and as an adult, my household today is much the same. Strangely, my 13-month-old only throws Rock, so he's incredibly easy to beat. The kindergardner kicks my butt, though.
posted by majick at 1:36 PM on September 11, 2002

Mo Nickels, clearly you haven't been keeping up with your issues of Think Three, the official newsletter of the World RPS Society-- specifically, the fascinating column The Myth of Dynamite Exposed.
posted by skryche at 1:49 PM on September 11, 2002

If you're interested in programming and meta-strategy, there's a bit of an explanation online of the tactics of Iocaine Powder one of the strongest RPS programs out there. It tied in the programming contest that zsazsa links above.
posted by vacapinta at 1:50 PM on September 11, 2002

There is an extension of jan-ken in Japan, played by (at least) junior high-schoolers. Immediately after playing jan-ken, the winner holds a fist out in front of the loser's face, saying "achi mitte hoi" and pointing either up, down, left, or right at the same moment they say "hoi." The loser looks in one of those directions at the "hoi" moment, and if s/he looks in the same direction the finger points, loses again. If the jan-ken loser looks in another direction, the "achi mitte hoi" process is repeated until s/he looks in the same direction as the pointed finger..

Also, in jan-ken, when both players show the same sign, they quickly say, "ai kora sho" and show their sign at "sho." So a game of jan-ken can sound like this, all super fast:

Jan ken PO, ai kora SHO, ai kora SHO, ai kora SHO, ai kora SHO! Achi mitte HOI, achi mitte HOI, achi mitte HOI! Ha ha ha, mitta, bakka. Mo i kai:
Jan ken PO, ai kora SHO! Achi mitte HOI! Yatta!
Tsumaranai, zo. Kora.
posted by dfowler at 2:14 PM on September 11, 2002

Dynamite (a single finger in the palm) beats everything.

Uh-uh. Scissor beats dynamite. (Cuts the fuse.)
posted by kayjay at 4:15 PM on September 11, 2002