Ra Riddles
Posted by Rob Herman at July 11th, 2007
Today, I was contemplating the idea of creating a Ra computer game. One hypothetical feature of this game would be to “auto-pass” a worthless auction. Turns out this feature won’t be seeing the light of day…
For both of the riddles below, you may use any play situation you can imagine, and you have complete knowledge of the game state; in particular, you can know exactly what tiles are still in the bag as well as each player’s face-down suns and score.
Riddle 1: The auction track contains one tile, Unrest (AKA Death of Civilizations). The sun in the middle is worse than any of your remaining face-up suns. You pull a Ra tile. Come up with a situation where you would want to bid on this auction. Make no assumptions about your opponents’ strategy–assume that whatever they do will be bad for you.
Riddle 2: The auction track contains nothing at all. The sun in the middle is worse than any of your remaining face-up suns. You pull a Ra tile. Come up with a situation where you would want to bid on this auction. For this one, you may make reasonable assumptions about opponents’ strategy; they may want, say, to maximize their own score or winning chances, not just hurt you.
Riddle 2: It is the last round, and counting all tiles won, you are 4 points behind the highest scoring player, who sits to your immediate right. You are not currently in the lead on Sun total. Your opponent on the right has one Sun left, the 1, and the lowest total Suns. If he swaps his Sun with that in the center, he will no longer have the lowest and hence, will be winning, but otherwise, the five point penalty will put you in the lead. The other three players have lower scores, but wish to score more points if possible. They also have better suns than you.
You pull the second-to-last Ra tile of the round. The three players to your left each pass (this Sun will not give them highest or lowest), and the last player throws his low Sun, hoping to upgrade and pull ahead. Therefore, you throw your Sun, knowing that on his turn, the player to your left will pull a tile. If it is not a Ra tile or a disaster, then should a player eventually call Ra, the player to your right will be unable to win the auction, since he’ll still have the lowest Sun and the other players will want points since the game is about to end.
In the meantime, it is likely that the last Ra will be pulled before the player to your right starts his turn with an empty board, which is the only situation in which he’ll be able to potentially win an auction. Therefore, the most likely course of action to win the game is to bid, and passing has a high probability of losing.
Fu Leng: I like that, and it’s close to what I had, which was:
It’s the third round of the game. Opponents A and C have already expended all of their suns. A has 4 points less than you counting only tiles, but currently has the highest sun total. Opponent B is no threat but still has suns. Opponent C is no threat and will certainly lose the 5 points for least suns. The bag has nothing of value for you–only rivers (no floods remaining, and you have none), civs that you already have, and pharaohs insufficient to change the pharaoh standings.
Opponent B is playing to maximize his score. Your last sun is the 13, and if Opponent B gets it, he will overtake Opponent A for highest sun total and you will win the game. Therefore, you bid your high sun, allowing B to take it at his leisure.
I added the “no assumptions about opponent’s play style” to Riddle 1 to make it different than “just like that, only you have no civs/three identical civs so the disaster doesn’t hurt you.”
Situation 1: You’re the only player left in the round, there are several civilizations left in the bag, all of which benefit you, and little or nothing else of value. You have 2 Suns left, and this is not the final Ra tile of the round. You have either no civs yet, or 2 pairs of civs of which the other 3 are all on the table already.
qualistarian: Ding!