How to cheat at Codenames; cheating at board games more generally

This is a good post for Christmas Day, with all of you at home with your families playing board games.

Dan Luu has an amusing post explaining how you can win Codenames by just memorizing the configurations of the 40 setup carts. The basic strategy is to play your best until you can figure out the unique configuration, then you win. The fun part is that if you’re playing against a team that hasn’t learned this memorization trick, then you can win even if you don’t guess any words yourself—you just take advantage of the config information that you get from their correct guesses (along with any wrong guesses that come up)! If both teams have memorized the 40 cards, then you get to a new level of strategy.

As Luu says, no one would want to play Codenames in this way. The whole point of the game is to guess the words; if you’re gonna do it by memorizing patterns, why play the game in the first place? On the other hand, he also points out that once this information is there, you can’t un-see it. So it’s a balance.

This comes up in the rules of Codenames itself: you’re not allowed to give clues that suggest the position of the word on the grid, nor are you allowed to make faces or otherwise give clues as people are guessing. It can be hard to avoid giving this information sometimes!

More generally, most games can be “cracked” through a backdoor approach in some way or another. Here’s how Luu puts it:

Personally, when I run into a side-channel attack in a game or a game that’s just totally busted if played to win . . . I think it makes sense to try to avoid “attacking” the game to the extent possible. I think this is sort of impossible to do perfectly in Codenames because people will form subconscious associations (I’ve noticed people guessing an extra word on the first turn just to mess around, which works more often than not — assuming they’re not cheating, and I believe they’re not cheating, the success rate strongly suggests the use some kind of side-channel information. That doesn’t necessarily have to be positional information from the cards, it could be something as simple as subconsciously noticing what the spymasters are intently looking at.

Dave Sirlin calls anyone who doesn’t take advantage of any legal possibility to win is a sucker (he derogatorily calls such people “scrubs”) (he says that you should use cheats to win, like using maphacks in FPS games, as long as tournament organizers don’t ban the practice, and that tournaments should explicitly list what’s banned, avoiding generic “don’t do bad stuff” rules). I think people should play games however they find it fun and should find a group that likes playing games in the same way. If Dave finds it fun to memorize arbitrary info to win all of these games, he should do that. The reason I, as Dave Sirlin would put it, play like a scrub, for the kinds of games discussed here is because the games are generally badly broken if played seriously and I don’t personally find the ways in which they’re broken to be fun.

It gets tricky sometimes, though. Consider those goofy words that are in the Scrabble dictionary but aren’t really words, for example ef (“the letter F”) or po (“a chamber pot”). These are not English words! On the other hand, when you’re actually playing and you see an opportunity for ef or po or whatever, it’s hard to deny yourself the opportunity. In that case, there’s an easy solution: the rules allow the players to agree on any dictionary ahead of time, so no need to use the Scrabble dictionary. On the other hand, this will annoy serious players.

There’s more of gray area with collusion, which can “break” almost any multiplayer game. In poker, collusion is a form of cheating. I don’t know how casinos or informal games monitor or enforce the rule against collusion, but you’re not supposed to do it. You’re allowed to lie in poker but not to cheat.

But what about a game such as Monopoly or Risk where bargaining is part of the game? Here’s a simple strategy in a 3-player game of Monopoly that will up your odds of winning from 1/3 to nearly 1/2: Before the game begins, pick one of the other players and agree to flip a coin, after which the winner of the flip will devote all their effort to helping the other player win. That’s easy enough to do: just buy whatever property that comes up and sell to the other player for $1. It won’t guarantee a win but it’s gotta take the win probability to very close to 100%. Similarly with Risk. Now, nobody’s gonna play this way because it’s no fun (except maybe once as a joke). To put it another way, “winning a game of Monopoly or Risk” does not have much positive value in itself; the fun is in winning the game legitimately. Again, though, there is a gray zone, and other players will rightly get annoyed if they see player A deliberately trying to help player B without there being a good reason in the context of a game. In Risk, “I won’t attack you here if you don’t attack me there” is a legitimate strategy, but “I don’t attack you because I want to help you win” is not so cool.

A few years ago I was playing a lot of online chess, and one thing I noticed is that some players would set up opening traps: clearly unsound sequences of moves that would get them a win if their opponents played naively and hadn’t seen the trick before. My thought was: Why do that? Winning against a stranger using a trap, what’s the point of that? Upon reflection, though, I decided to not be so bothered by this. If you try to spring a trap, then the fun part is when the trap fails and then you have to get out of a bad position of your own devising. So, all good.

Years ago I read the book Thursday Night Poker by Peter Steiner. One thing Steiner discusses is that in a casual game you can often do just fine by playing really tight, a strategy that won’t work against good players but can make you steady money if some of the people at the table are just playing for fun. As Steiner says, though, most of us are not playing in a friendly poker game with the goal of maximizing our dollars. We’re playing poker for fun, and “action”—getting involved in hands, making betting decisions, going up against the other players—is where the fun is at. No poker player would be a “scrub”—you’ll always take advantage of any legal way to win, it’s not like you’d ignore relevant information that someone reveals—but, even in poker, winning is not the only goal.

All of this is kind of obvious, but as Luu discusses, sometimes it needs to be pointed out, to push against naive models of the world. Also, the bit about the Codenames cards is cool—I’d never thought about that!