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Arimaa >> General Discussion >> Arimaa without captures?
(Message started by: gatsby on Apr 30th, 2008, 9:07am)

Title: Arimaa without captures?
Post by gatsby on Apr 30th, 2008, 9:07am
Would arimaa be playable if there were no captures? I know that Omar thought of it at some stage of arimaa design...

Title: Re: Arimaa without captures?
Post by aaaa on Apr 30th, 2008, 9:42am
I really doubt it. I think that any reasonably competent player who will always have all his pieces at his disposal should be able to prevent goal and immobilization for an indefinite amount of time.

Title: Re: Arimaa without captures?
Post by jdb on Apr 30th, 2008, 5:51pm
If there were no captures, a player could attack with everything...

Title: Re: Arimaa without captures?
Post by Fritzlein on Apr 30th, 2008, 6:15pm
I don't think Omar ever experimented with a no-capture version with a full set of 16 pieces per side.  I'm not sure but I think he had at most 11 pieces per side in the no-capture variants.

If there is one thing Omar's play testing showed definitively, it is that the way a game actually plays can be quite different than one's intuitions based on just the rules.  My intuition about removing capture from Arimaa but keeping all other rules is that it would be a huge logjam every game with no way to make progress.  It's hideous in my imagination.  But if you playtested that variation and it turned out that forcing goal was somehow possible, I wouldn't be too surprised, and it might even have an impact on the way I play the standard game.

Title: Re: Arimaa without captures?
Post by omar on May 2nd, 2008, 3:38pm
Yes, you are right Karl, we did try a version without any trapping but it didn't use the full set of pieces; didn't include the queen and four pawns.

Even with the fewer pieces the game would get a bit jammed up and crowded in the middle. Also the game felt a little dull because one did not have to be careful of suddenly losing a piece.

Title: Re: Arimaa without captures?
Post by gatsby on May 7th, 2008, 7:12am
But the game could always be decided by score when it reaches some stablished number of moves, say 100.

Or we could decide games by using this rule:

If the game hasn't ended by move (say) 100, the game will be won by the player who has advanced more squares with one of his rabbits than the other player with any of his ones. If the tie persists, the game will be won by the last player who has had this kind of advantage in a previous position...

It is not very elegant, I know, but I am just trying to figure out how we could make it playable. Arimaa is of course much better than this...

Title: Re: Arimaa without captures?
Post by aaaa on May 20th, 2008, 1:17pm
I wonder what kind of game we would get if traps could not be protected. Given that there would be a tension between not wanting lesser pieces hanging around the trap, while also not wanting to leave open a gap for a rabbit to get through, it's not obvious to me it would be that unplayable of a game. Would probably be a fast, racing one.

Title: Re: Arimaa without captures?
Post by 99of9 on May 20th, 2008, 10:35pm

on 05/20/08 at 13:17:23, aaaa wrote:
I wonder what kind of game we would get if traps could not be protected. Given that there would be a tension between not wanting lesser pieces hanging around the trap, while also not wanting to leave open a gap for a rabbit to get through, it's not obvious to me it would be that unplayable of a game. Would probably be a fast, racing one.

Interesting.  I think this might emphasize the elephant domination even more.  I think both players would want their elephant forward.

Title: Re: Arimaa without captures?
Post by Fritzlein on May 21st, 2008, 8:13am
I have a hunch that Arimaa without capture defense would be a straightforward race.  An elephant could cut a path for a rabbit to reach goal, and not even the opposing elephant could stop it.  Thus the only viable strategy would be to use your own elephant to cut a path to goal even faster.  The distinctions from cat to camel would largely collapse, as all of those pieces would be just elephant fodder.  Once we got good at racing, it would probably become like Halma (Chinese Checkers) where experts can count out many moves in advance exactly how long it will take them to get their marbles home, and races are usually decided by one or two moves.  In standard Arimaa, the fact an elephant can be thwarted either permanently by an opposing elephant, or temporarily by a group of small pieces, creates both interesting deadlocks and interesting races.

My intuition is that eliminating capture would make the game unwinnable, but eliminating capture defense would make the game unstrategic.  The same caveats apply, though: intuitions are often wrong, you have to play test, it takes a long time to be sure, etc. etc.  Maybe there would be elements of defense which introduce strategic intricacies that are not obvious from the rules.

Title: Re: Arimaa without captures?
Post by mistre on May 21st, 2008, 10:28am
It is amazing how Arimaa was developed to be so balanced between offense and defense.  Making any changes to the rules would likely upset that balance.  Arimaa without captures would just turn into a boring roadblock, while Arimaa without protected traps would dissolve into a pure calculated race (as Fritzlein said).

I think Arimaa is perfect as is, but if anyone wants to experiment with variants - here are some ideas:

1) Have a piece (a mouse) that could push the Elephant, but can be pushed by all other pieces except rabbits and the elephant.  (this idea has already been posed in earlier threads).

2) Replace one Horse with a piece between the strength of Camel and Horse. (this was also proposed before).  I think Lion was proposed, but this could be any other animal of our choosing (Alligator, Rhino, Giraffe, etc.)

3) Board Sizes/No of traps.  I don't think this has been talked about, but you could develop custom boards which or slightly bigger/smaller, have fewer traps, more traps, traps in different locations, etc.  

Two specific ideas -  9x9 board with 5 traps (1 in the center, the others in normal positions OR 4 traps in a diamond configuration.)  Players could either have 2 additional pieces or just leave two blank spaces in their setup rows. Call it Arimaa Deluxe.

On the other end of the spectrum, shrink the board to 5X7, still 4 traps, but they are only one space apart.  Each player has one of each piece and 5 rabbits. Call it Arimaa Jr.

Arimaa already has amazing depth as is, but creating variants could lead to something fresh and exciting for old vets or designed to pull new players in (an easier version).





Title: Re: Arimaa without captures?
Post by ChrisB on May 22nd, 2008, 12:25am
I too find standard Arimaa to be "just right", yet am intrigued by the variants mistre described.  I'm especially curious how Arimaa Jr. (5X7 board) would play out.  I'm guessing that immobilizations would happen more often.

The five trap version of Arimaa Deluxe has also been discussed before, see:

http://arimaa.com/arimaa/forum/cgi/YaBB.cgi?board=talk;action=display;num=1173723636

If some day computers surpass humans in Arimaa by simply thinking much faster rather than smarter, a larger scale arimaa may be the ticket for humans to regain supremacy:

This could be accomplished by some combination of a larger board, more pieces, more steps per turn, and possibly even using hexagons instead of squares.  Adding more steps per turn should be especially confounding for computers, since the branching factor would increase dramatically.  However, we would likely need to add some movement limitation rules to avoid easy captures and goals.  One possible limitation rule, which is simple but may be overly stringent, is prohibiting pushes, pulls and rabbit advancements after the first four steps.

Title: Re: Arimaa without captures?
Post by mistre on May 22nd, 2008, 5:46am
I did not know that someone else had the idea of a 9x9 board before.  Thanks for pointing out that thread, Chrisb.

Arimaa Jr. (5x7 board) might work better with 3-step moves instead of 4 as trap density would be higher.

Title: Re: Arimaa without captures?
Post by ChrisB on May 22nd, 2008, 7:49am
It's interesting that two players came up with the exact same board for an expanded arimaa!

Three vs. four steps for 5x7 arimaa is an interesting question.  Maybe four steps would still work despite the higher trap density since a single piece could defend two traps. But, then with four steps might it be too easy to immobilize the other side? [edit]  It would be interesting to test out both alternatives.

Title: Re: Arimaa without captures?
Post by Arimabuff on May 24th, 2008, 8:11am
As far as I am concerned, Arimaa without captures would be boring. Every major board game has captures: Chess, Checkers, Othello, Go... you name it. I don't think these games would have achieved the same level of popularity without captures.

Title: Re: Arimaa without captures?
Post by Werner on Jul 11th, 2008, 4:03am
How about 9x9 with 4 traps (c3, c7, g3, g7)?

Each side with 9 rabbits, 2 cats, 2 dogs, 2 horses, 2 camels and 1 elephant?

Title: Re: Arimaa without captures?
Post by PMertens on Jul 11th, 2008, 10:43am

on 07/11/08 at 04:03:41, Werner wrote:
How about 9x9 with 4 traps (c3, c7, g3, g7)?

Each side with 9 rabbits, 2 cats, 2 dogs, 2 horses, 2 camels and 1 elephant?


I personally would prefer the current asymmetric version since it imho allows for more variations even though I am a supreme-commander fanboy and would in generall prefer the 1000x1000 board with 1000 rabbits, 400 cats, 300 dogs, 200 horses, 98 camels, 1 elephant and 1 nuke ... and a few more traps :-)
(second part of  my post was a joke ... sorry)

Title: Re: Arimaa without captures?
Post by Arimabuff on Jul 11th, 2008, 12:03pm
How about Arimaa based on chinese chess structure?

http://upload.wikimedia.org/wikipedia/commons/4/41/Xiangqiboard.png



That is 5 rabbits, 1 elephant, 2 camels, 2 horses, 2 dogs, 2 cats and 2 rats. A rat being weaker than a cat and stronger than a rabbit. The traps being on C3 and G3 and symmetrically on the other side. At the start of the game the pieces can be positioned anywhere (even on the traps) on the first 4 rows of your side of the board.

I think it'd be worth a try.

Title: Re: Arimaa without captures?
Post by The_Jeh on Jul 11th, 2008, 9:34pm

on 07/11/08 at 10:43:00, PMertens wrote:
I personally would prefer the current asymmetric version since it imho allows for more variations even though I am a supreme-commander fanboy and would in generall prefer the 1000x1000 board with 1000 rabbits, 400 cats, 300 dogs, 200 horses, 98 camels, 1 elephant and 1 nuke ... and a few more traps :-)
(second part of  my post was a joke ... sorry)


I don't know about a 1000x1000 board, but it sounds like you might want to start studying the 36x36 shogi variant known as "Tai Kyoku Shogi." Created in the 16th century, Taikyoku Shogi, which was rediscovered in 1997, is thought to be the most complex chess variant ever made.

http://en.wikipedia.org/wiki/Taikyoku_shogi

Before the rediscovery of Taikyoku Shogi, the 25x25 Tai Shogi was thought to be the grandest chess relative of all time. You can download a computer program that plays it here:

http://trout.customer.netspace.net.au/

Title: Re: Arimaa without captures?
Post by PMertens on Jul 15th, 2008, 10:40am

on 07/11/08 at 21:34:19, The_Jeh wrote:
you might want to start studying the 36x36 shogi variant known as "Tai Kyoku Shogi." Created in the 16th century, Taikyoku Shogi, which was rediscovered in 1997, is thought to be the most complex chess variant ever made.

http://en.wikipedia.org/wiki/Taikyoku_shogi
http://trout.customer.netspace.net.au/


wow ... that looks indeed complex ...

I am glad that Omar tried to make the arimaa-rules as simple as possible (while keeping the game complex).
The creator of that shogi-variant probably had something else in mind.

Deeply impressed ...

Title: Re: Arimaa without captures?
Post by omar on Jul 22nd, 2008, 8:50am
A while back I played shogi online against computers a few times to get a feel for the game. I always have a hard time trying to remember the different movement of different pieces. Having even more pieces with different movements I think would make it extremely hard. The 36x36 version is probably hitting the limits of human playability. It might have been a variation that was tried, but after actual play did not really catch on.




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