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        Arimaa >> General Discussion >> Alternative Rule - Mouse or Rat
        
(Message started by: ocmiente on Jan 13^th, 2010, 1:55pm)

Title: Alternative Rule - Mouse or Rat
Post by ocmiente on Jan 13^th, 2010, 1:55pm

Has anyone tried the alternative rule playing with a mouse or a rat? If so, how well did it work? Were the strategies significantly different?

After looking through the forum, I have seen it mentioned before but I didn't find any opinions about it - if it's there, please provide a link to the discussion.

There was another post about the Chinese translation of Arimaa, which mentioned "Jungle Chess", which I played with my kids last week, and it made me wonder about the Rat, or Mouse, in that game.

It would be interesting if there was another piece type, a Rat, that would be weaker than any other piece except the elephant. No other special powers, it would just be the weakest piece (even weaker than Rabbits), but it would be stronger than the elephant (it could scare it away, perhaps?).

Whether this would mean one fewer rabbit, or one fewer of the other pieces, I'm not sure. But, related to this post, if Arimaa had something like the Rat in "Jungle Chess" (or the Spy in Stratego), it might reduce any perception that "it's all about the elephant".

I wonder if "Jungle Chess" was any influence on the design of Arimaa, and if it was, why the Rat was left out. Maybe it would break the ability to easily use chess pieces for the game? Or, maybe, it made it too difficult to take control of an opponent's trap space?

If only I had infinite time to try out all of the possible variations of the game!

The other discussion of the rat I found on the forums suggested that the rat would be stronger than the rabbits, but I think making it weaker might be more interesting.

I also like the idea of replacing one of the rabbits, because that would make the rabbits slightly more precious - since there would be fewer of them.

Title: Re: Alternative Rule - Mouse or Rat
Post by Adanac on Jan 13^th, 2010, 2:18pm

on 01/13/10 at 11:45:04, ocmiente wrote:

There was another post about the Chinese translation of Arimaa, which mentioned "Jungle Chess", which I played with my kids last week, and it made me wonder about the Rat, or Mouse, in that game.

It would be interesting if there was another piece type, a Rat, that would be weaker than any other piece except the elephant. No other special powers, it would just be the weakest piece (even weaker than Rabbits), but it would be stronger than the elephant (it could scare it away, perhaps?).

Whether this would mean one fewer rabbit, or one fewer of the other pieces, I'm not sure. But, related to this post, if Arimaa had something like the Rat in "Jungle Chess" (or the Spy in Stratego), it might reduce any perception that "it's all about the elephant".

I wonder if "Jungle Chess" was any influence on the design of Arimaa, and if it was, why the Rat was left out. Maybe it would break the ability to easily use chess pieces for the game? Or, maybe, it made it too difficult to take control of an opponent's trap space?

If only I had infinite time to try out all of the possible variations of the game!

This has been discussed a few times in the past, and I’m convinced that Arimaa only works because of the invincible elephant. Imagine, for example, a gold dog at the beginning of the game standing on the c2 square. It can feel very safe standing there because there are hordes of other gold pieces around to help it protect the c3 trap. If that gold dog wanders 3 steps north to c5 alone it will be instantly devoured. The gold army "only" needs to advance its horde of pieces from the southwest to the northwest and the gold dog will be perfectly safe on c5, once again surrounded by its friends – great, sounds easy right? Well, no. Theoretically, the gold camel could try to clear room in the northwest for the dog. However, an advance by the gold camel will instantly draw attention from the silver elephant, thwarting the attack. A gold horse could try to control the trap by occupying the b6 square. The problem is that it has become universal strategy for the silver player to always station a silver horse or camel on the b6 square (and g6, too) in the opening phase. So, the gold horse won’t succeed in its attack either. Naturally, it becomes the elephant’s duty to open the door for the lesser pieces to advance. In practice, I find that most successful attacks are the result of an attacking elephant holding a key square (like d6, in this example), or by pulling/pushing/chasing away powerful defenders before a successful attack becomes possible. The general exceptions to the “elephants always initiate the attack rule” are:

1. The silver elephant is far away, allowing the gold camel to attack on the opposite side.
2. The b6 square is weakly defended and the gold horse advances to take it, followed by a few friends.
3. The board is heavily depleted and weaker pieces, including rabbits, can advance more safely.

But suppose your opponent plays defensively – very defensively, as is common with many players in the opening phase. Imagine your opponent always leaves the elephant near the middle, always keeps strong defenders on b6 and g6 without exception and avoids exchanging pieces whenever possible. How do you attack now? Well, “with extreme difficulty” is the answer. Against a determined defender, your elephant must work hard to exploit even the slightest crack in the opponent’s defences before the weaker pieces can profitably join in. But what would happen if there were a mouse (or rat) on the other side of the board? The way I see it, attacking would become impossible as there would no longer be any pieces brave enough to walk into enemy territory. We really should try to test the idea in real games sometime, just to be sure – but I’d be shocked if intimidating the one piece that seems to initiate all the action would actually improve Arimaa.

You did bring up an interest point that I've never seen before. In the past, most people have suggested replacing a rabbit with a mouse or rat. But what if we replace a different piece? If each player had the option of beginning the game with either a camel or a rat that might be more interesting! If the gold player decided to include a rat on his initial piece placement and leaving the camel out of the game, while the silver player responded by placing his camel on the board (leaving the silver rat out of the game), then it’s not clear which side would have the advantage. And each player would have new avenues for attack that don’t exist in the original rules. That might be a fun experiment.

Title: Re: Alternative Rule - Mouse or Rat
Post by Fritzlein on Jan 13^th, 2010, 7:09pm

on 01/13/10 at 13:55:48, ocmiente wrote:

Whether this would mean one fewer rabbit, or one fewer of the other pieces, I'm not sure. But, related to this post, if Arimaa had something like the Rat in "Jungle Chess" (or the Spy in Stratego), it might reduce any perception that "it's all about the elephant".

I think it would be a shame to react to perceptions of problems rather than reacting to actual problems. As it turns out, Jungle Chess is a completely broken game. There is a purely defensive strategy that can keep the other player from ever winning. Meanwhile Arimaa is not broken. There is no defense (at least none known to us) that can stop the other player from winning in Arimaa.

I can understand how you would guess that Arimaa tends to stalemate due to the invincible elephant, and guess that the Rat keeps Jungle chess fluid, but both of your guesses would be wrong.

Quote:

I wonder if "Jungle Chess" was any influence on the design of Arimaa, and if it was, why the Rat was left out.

I think that Omar didn't even know about Jungle Chess until after he designed Arimaa, but you would have to ask him.

Title: Re: Alternative Rule - Mouse or Rat
Post by ocmiente on Jan 13^th, 2010, 8:36pm

Sorry. I did not mean to suggest that there is anything wrong with the game. On the contrary, I'm very happy with the rules of Arimaa as they are and would not change a thing.

I'm just wondering if anyone has tried this alternate rule, and if so, how it went. I think it would change the game so substantially that any strategies that work well with the standard version would have to be rethought - but I'm not sure. I plan on trying it out soon, but my competition usually consists my kids, who aren't yet that much competition

Regarding Jungle Chess, even if Omar was not aware of the game, the similarities are too strong not to think that there might not be some connection. Specifically: the pieces move one space horizontally or vertically, the pieces are animals, the pieces have a defined rank, the elephant is the strongest piece, there is also a cat and a dog, the goal is to reach a point on the board (the den in this case), and there are trap spaces (the function is different, but the basics of a trap space idea is there). Even if some of the ideas did not come from this game - there are probably links to other games that helped bring Arimaa about. To think that Arimaa was created out of the blue would seem just as far fetched as to think that there were not influences from other games - like chess, for instance (number of pieces, pieces can be substituted, 8x8 board).

The major differences include: movement of only one space per turn rather than four, Jungle has a two significant rivers on the board that change how the pieces move, capture in Jungle is the same as for Stratego (strongest piece wins when they meet), but the most significant difference (I think) is that Arimaa has the push/pull mechanism. So far, I can't recall another game that works like that - but I would not be surprised if there were some other game with the push/pull feature (few things new under the sun). I think that the push/pull mechanism is one of the best features of Arimaa that really sets it apart.

Edit: I found another game that has the push/pull mechanism: "Dynamo Chess"

So I'm still wondering if anyone has tried the alternate rule or something like it, and if so, how it went. I would really be interested to know if Omar has tried it when developing the game and found it to be unbalanced somehow - as Adanac suggests.

Quote:

I can understand how you would guess that Arimaa tends to stalemate due to the invincible elephant, and guess that the Rat keeps Jungle chess fluid, but both of your guesses would be wrong.

Well, no. I wouldn't guess any of that. I've played enough to know that none of that is the case. However, I think that it might be possible that with a Rat there would be even more teamwork involved with the pieces. Someone must have tried it out before, right?

Title: Re: Alternative Rule - Mouse or Rat
Post by 722caasi on Jan 13^th, 2010, 8:52pm

This was play tested, on 8x8 and 9x9 boards (replacing a cat on 8x8) back in 2007. See this link for playtest results:
http://arimaa.com/arimaa/forum/cgi/YaBB.cgi?board=talk;action=display;num=1174411328

Title: Re: Alternative Rule - Mouse or Rat
Post by Fritzlein on Jan 14^th, 2010, 8:52am

on 01/13/10 at 20:36:52, ocmiente wrote:

I'm just wondering if anyone has tried this alternate rule, and if so, how it went. I think it would change the game so substantially that any strategies that work well with the standard version would have to be rethought

I think you are absolutely correct on that point.

Title: Re: Alternative Rule - Mouse or Rat
Post by ocmiente on Jan 14^th, 2010, 9:58am

on 01/13/10 at 20:52:02, 722caasi wrote:

Thanks! That is exactly what I was looking for - and the discussion of the strength of the camel was interesting because the mouse seems to have the same effect in Jungle Chess.

Regarding the 8x8 vs. 9x9 board, I was wondering about that too... Seems like the number of pieces might need to be increased to compensate for the increase in the number of pieces on the board.

Regarding the mouse being stronger than the rabbits or not, I was thinking that if it's weaker it introduces new behavior that wasn't there before (rabbits can move a piece out of the way, so a mouse would only be effective in blocking a goal in combination with other pieces) - so I think I'll try that version soon (8x8 board, replace a rabbit with a mouse, mouse does not score a goal like a rabbit, mouse weaker than all other pieces except the elephant).

Title: Re: Alternative Rule - Mouse or Rat
Post by omar on Jan 15^th, 2010, 11:36am

I did try a version where the elephant could be pushed/pulled by the mice. I don't remember exactly why now, but it didn't seem to work. I think it made the elephants very weak and once they were exchanged the camels become dominant and it becomes similar to the way it is now. But more often the elephants were held back and the game length seemed to get longer. I also didn't like that it introduced an odd exception to the hierarchy rule.

Because I was trying to make the game playable with a chess set I didn't even consider the possibility of replacing just one rabbit or stronger piece with a mouse. In the variation I tried all rabbits/pawns became mice.

Replacing just one rabbit with a mouse might actually work. I was tempted to try that after IdahoEv mentioned it, but never got around to it. I would still guess that the game length would be longer for this variation.

Title: Re: Alternative Rule - Mouse or Rat
Post by ocmiente on Jan 16^th, 2010, 10:59am

I played a game with a mouse this morning (8x8 board, replace a rabbit with a mouse, mouse does not score a goal like a rabbit, mouse weaker than all other pieces except the elephant)

Since it has taken hundreds of games for me to figure out how to play the official version of Arimaa (and I'm still not very good at that), and several years and several bots for the community to develop good strategies for it, I realize that one game is hardly enough to determine if it's playable.

However, I thought the game was very interesting with a mouse, and I think it adds new behavior to the game. I expect I'll play it many more times with a mouse.

I found that it was possible to frame a mouse with an elephant - but the elephant had to be supported by three other pieces to complete it's side of the frame. I also found that figuring out when a piece is frozen or not becomes more complicated - if not confusing - but I expect that would settle out after a while. I think that even with the added complexity, computers might gain some edge because I think humans might not deal with the new complexity as well. On the other hand, I think in human to human games, it might just be a fun alternate way to play.

Now, I would like an expansion pack for the board game, please :) It would consist of 4 pieces, two mice and two lions (or rhinos, or some other animal... a piece between the strength of a camel and a horse). I haven't tried to play with a lion yet, but I'm sure that would be fun too.

Title: Re: Alternative Rule - Mouse or Rat
Post by Fritzlein on Jan 16^th, 2010, 12:24pm

on 01/16/10 at 10:59:18, ocmiente wrote:

Now, I would like an expansion pack for the board game, please :) It would consist of 4 pieces, two mice and two lions (or rhinos, or some other animal... a piece between the strength of a camel and a horse). I haven't tried to play with a lion yet, but I'm sure that would be fun too.

Zman won't produce an expansion pack for Arimaa until the original print run sells out, and it doesn't look like the original print run will sell out unless Arimaa gets some recognition (like winning an abstract strategy game award), and I expect any recognition would come on the basis of the depth of the original game.

That said, if there is an expansion pack, it should be loaded up with as many variants as possible. There should be dice with numbers 1, 2, 3, 4, 4, 4 for Omar's "roll to see how many steps you get" variant, and there should be eight discs that snap on the the bottom of the rabbits for Omar's "concealed suicide bomber" variant, and there should be at least three new types of animals in additional to the mouse, (say lion, hippo, goat) for people who want to try "no duplicate pieces" Arimaa.

Then with all the extra equipment there should be at least a dozen different rule proposals. IdahoEv previously went into many different ways one could play just with a mouse piece. The more different rule sets you suggest, the more you give variant-lovers their money's worth.

My point is that once you start selling variants, you are selling variety, not strategic depth or assurances that the game has been massively play-tested and will never be busted. We have no reason to believe that a game with one mouse and seven rabbits is better or worse than a game with two mice, four rabbits, a hippo, a concealed suicide bomber, and movement dice. Since the promise of a great game is not included in the expansion pack, why not take variety of rules to the max? Don't rule anything out. Let your creativity run wild.