Life In 19x19

QUENCH

Introduction

Quench is a series of finite Go variants with banned or restricted group creation subsequent to captures. Area scoring is used, and suicide of any number of stones is not allowed. The ko and superko rules are not used. All other Go rules apply unless otherwise specified.

Play

The variants are sorted from most to least different from Go.

Variant #1

Once a player makes a capture for the first time, that player can’t create any more groups for the rest of the game.

Variant #2

Once a player makes a capture for the first time, that player must perform exactly one of the following actions on every following turn for the remainder of the game:

• Pass.
• Place one stone of his color without creating any group.
• Place one stone of his color so that it joins two or more groups and another one so that it creates a new group, in that order.

Variant #3

When a player makes his first capture, he must place a coin next to himself, tails up. From then on, the following rules apply:

• When a player joins two or more groups, he must place his coin heads up.
• When a player creates a new group, he must place his coin tails up.
• A player’s move can only create a new group if his coin is heads up at the start of his turn.

Variant #4

Just like variant #3, except that the coins are placed heads up when they’re introduced.

Sample games

Variant #1

Sample 11x11 Quench game

Variant #3



Author’s notes

These variants are very different from Go, but I wonder how they compare to it in terms of depth. Once a player makes a capture, the game becomes easier than Go, but before that point there's a difficult strategic dilemma between capturing enemy groups in exchange for reduced move options thereafter and preserving your flexibility by letting threatened enemy groups escape. Also, the disincentive to make the first capture in variant #1 seems to be strong enough as to delay it for the most part of the game. When it finally happens, it's a turning point comparable to the choosing of colors in Unlur and Mind Ninja, but without the unequal goals.

Variants #2 to #4 make for a more challenging post-capturing phase by allowing players to create a new group every time they join two or more of their existing groups. This adds another strategic layer to the pre-capturing phase as well. Since having good prospects of joining some of your groups is crucial to success in the second phase, your play during the first phase must be adjusted accordingly. The dilemma is served again: there's an increased incentive to create many groups, but that also means more vulnerable groups.

What defines a group to determine if you can play a move or not?

I will venture to guess he means "orthogonally connected", which seems to be the standard understanding of group in abstract game design circles. But it's just a guess.

That brings up a whole host of other questions, though. For example, is this one group, or more for each side?

Click Here To Show Diagram Code

[go]$$W
$$ -----------------
$$ | . B B O . . . .
$$ | B . B O . . . .
$$ | B B O . . . . .
$$ | O O O , O . . .
$$ | . . . . . . . .
$$ | . . . . . . . .
$$ | . . . . . . . .[/go]

I think it's safe to say that most go players would consider each side to have one group here, but the orthogonal connectedness gives 2 and 3, respectively.

skydyr wrote:What defines a group to determine if you can play a move or not?

A group is defined exactly as in Go, i.e. a set of orthogonally adjacent, like-colored stones.

skydyr wrote:That brings up a whole host of other questions, though. For example, is this one group, or more for each side?

$$W
$$ -----------------
$$ | . B B O . . . .
$$ | B . B O . . . .
$$ | B B O . . . . .
$$ | O O O , O . . .
$$ | . . . . . . . .
$$ | . . . . . . . .
$$ | . . . . . . . .

Click Here To Show Diagram Code

[go]$$W
$$ -----------------
$$ | . B B O . . . .
$$ | B . B O . . . .
$$ | B B O . . . . .
$$ | O O O , O . . .
$$ | . . . . . . . .
$$ | . . . . . . . .
$$ | . . . . . . . .[/go]

Black has 2 groups and White has 3 here. That's the definition of group which is used in all the Quench variants.

To be perfectly explicit, go rules do need the concept of group so that you can check for capture, but unlike many abstract games (Slither, Oust, Sygo, Symple come to mind), you can give an informal explanation of the rules without talking about groups.

For that reason, to a go player, "group" usually does not mean a set of orthogonally connected stones of the same color, but a set of stones that "go together", in some looser sense. Groups can be disconnected.

Click Here To Show Diagram Code

[go]$$ We talk about White's two stone group.
$$ ---------------------------------------
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . X . W . . W . X . . . . . . . |
$$ | . . X , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . , . . . . . , . . . . . , . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ | . . . . . . . . . . . . . . . . . . . |
$$ ---------------------------------------[/go]

Here's a good summary of the word group in go, along with alternatives unit, chain, and string.

It's nutso, Luigi. Out of curiosity, what strategic depths do you think it has? You are very coy when you introduce these games so I am not sure whether you are being modest, or just really haven't thought about whether the game has any strategic aspects yet.

jts wrote:It's nutso, Luigi. Out of curiosity, what strategic depths do you think it has? You are very coy when you introduce these games so I am not sure whether you are being modest, or just really haven't thought about whether the game has any strategic aspects yet.

The "Author's notes" section in my first post reflects most of my current thoughts on the game's strategy. I have only played it a couple of times against other people (variant #1 once and variant #2 once). The game works, but my understanding of its strategic intricacies is still necessarily limited.

I was expecting seasoned Go players could help here. Any comments on the expected behaviour of the game are welcome. I'd also love to play a test game on a Malkovich thread against anyone interested. It would be a better illustration than anything I can say.

I recommend trying either Variant #1, which is the purest implementation of the general concept, or Variant #3, which strikes a good balance between simplicity of rules and flexibility of play. I don't like Variant #2 much myself because the frequent double moves in the second phase of the game are a bit too much of a change of pace for my taste, but that's subjective.

As a go player, I think I have zero intuition.

I suspect these rules make it so that if you are the first to capture a stone, you will lose the game very quickly, except for Variant 2, which I don't have any intuition for.

As I understand the game, Luigi, after the first capture it will be impossible to kill enemy groups, no matter how improbable these groups seem to a go player. In go, killing techniques require being able to create new strings at will.

I've noticed that both you and Christian Freeling create "variants" that show very little sensitivity to how go is played, which raises questions as to whether you've played it much. If you want to create variants of go that are both fun and meet your strict standards for rule simplicity, design a game you find strategically deep first, then see if you can finesse the cycles. You're a bit like the drunk searching for his keys under a lamplight. But I'm not sure whether it's possible to see strategic depths in a go variant before you've explored the strategic dimensions of go itself!

If you are just interested in the strategic ramifications of penalizing the first capture, play a variant where the first capture loses X points. If you are interested in the strategic ramifications of being forced to reconnect your groups, play a variant with a group tax of Y points at the end of the game. (NB, for the original game of Go, Y=2, not 0.)

Shaddy wrote:I suspect these rules make it so that if you are the first to capture a stone, you will lose the game very quickly, except for Variant 2, which I don't have any intuition for.

It's true that capturing enemy stones early in the game with few groups to grow is an almost guaranteed loss, but that only means the game requires a very different approach from Go. Good players will try to delay the first capture until the size of the captured group and the number of groups he has to grow give him good winning prospects. Assessing the value of that capture relative to the loss of flexibility is the key strategic point of the game and creates a build-up of tension until the first capture is finally made. From that point onwards, the game becomes a trial of sorts where the player who made the capture will have to prove that his assessment was right.

The strong disincentive to capture also gives room to a powerful counter-strategy: chasing a big enemy group so that the opponent is forced to make a small capture too early in the game in order to save it. The chasing player's strategy will succeed if the enemy group is so big that capturing it would guarantee a win despite the loss of move options from that point.

Shaddy wrote:I suspect these rules make it so that if you are the first to capture a stone, you will lose the game very quickly, except for Variant 2, which I don't have any intuition for.

Yes, what I meant is that given the fact that capturing a stone is so bad, I have no intuition for what play would be like.

Luigi: I suspect the threat to capture a big group is not realizable, at least in version 1. The issue is that in regular go, you can threaten to capture a big group because of escalation. You threaten to capture a smaller group, and the opponent decides he can't allow it and/or can't live in an unduly slow/passive way, and the resulting dynamic makes the group grow without yet securing life. The point is that the initial threat to capture is a threat. In your game, it's not really a credible threat, because capturing that smaller group would be a losing move.

Do you have a link to a completed game? I can't convince myself that version 1 is a game you could reasonably play.