
5D chess game where pieces time travel - jelliclesfarm
https://www.5dchesswithmultiversetimetravel.com/
======
sixstringtheory
Previously discussed:
[https://news.ycombinator.com/item?id=24054313](https://news.ycombinator.com/item?id=24054313)

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tripplyons
It's fun and was worth buying, but I'm pretty sure it's 4D. In the in game
manual, it even says that there is an unused spacial dimension in the in-game
rulebook.

First, you have the 2 dimensions that pieces can move in in regular chess. The
third dimension is the fact that pieces can move back in time a certain amount
of boards depending on the move, creating a different timeline. The fourth
dimension is how pieces can move into different timelines using one their
movement dimensions.

~~~
hateful
I think it's 5D because it just skips the "our" 3rd dimension. Just because
Chess movements are in a 2D space, doesn't make the 3rd dimension temporal.
You can move in 2 spatial dimensions and 1 temporal one (the 4th), but when
you move through the temporal one you create a split in the 4th one...

"5 - a split"
[https://www.youtube.com/watch?v=0ca4miMMaCE](https://www.youtube.com/watch?v=0ca4miMMaCE)

Of course I'm assuming you're all playing the game in the same universe I am!

In other words - the game USES 4 dimensions, but is PLAYED in 5D.

~~~
gibspaulding
One could argue that traditional Chess still has 3 dimensions since knights
wouldn't be able to "jump" in true 2-space.

~~~
tutfbhuf
You can even play chess without any physical or digital 2D or 3D board.
Blindfold Chess is a thing. The chess board in my mind is 3D, but this may
vary from person to person. Game position and moves can be stored in 1D, just
text.
[https://en.m.wikipedia.org/wiki/Portable_Game_Notation](https://en.m.wikipedia.org/wiki/Portable_Game_Notation)

~~~
munk-a
Eeeh I'm not buying 1D - by the same logic all shapes can be stored in 1D by
writing their descriptive formulae in a linear series of text.

~~~
tutfbhuf
Well you cannot play football, because this requires physical activity. But I
think, yes, for games that just require 1D information exchange and thought,
that's all it needs. Any 2D, 3D, 4D representation of that 1D information is
just optional e.g. for convenience reasons, because people like to move around
physical 3D chess pieces instead of having to remember chess positions and
playing blindfold.

~~~
munk-a
I can precisely record football in one dimension - in fact some folks over at
EA have been making a whole bunch of money simulating football using a linear
data stream for quite a number of years. If you dislike the simulation then
bear in mind that most people who "observe football" are observing a 1D data
stream that's being read in to cause some photons to bounce around.

Saying that you can describe something in X dimensions doesn't make that thing
an X dimensional object - or well it might depending on how you define
dimensionality, but if you do it that way then everything is 1 dimensional.

~~~
tutfbhuf
I mean the difference is that I can actually play (not only observe) chess
with just 1D representation of the game. Whereas football requires you to act
physically in 3D space. But you are right, I would also consider "virtual
football" e.g. simulated by a computer as 1D.

~~~
munk-a
I disagree - you can play a game with the same rules as chess in 1D but you
can't move your pawn forward on the board in 1D. Chess is a cerebral game so
it's easier to abstract it down to entirely be about the will of the movements
but those movements aren't committed (in a normal game of chess) until the
pieces are actually moved.

So I think you can tactically play football and chess equivalents in 1D, but
the actual movements required to execute the game still require three
dimensions and Chess remains a game that is pretty naturally aligned with the
requirements of two dimensional space.

This is very pedantic at this point but I think the naive and natural
assumptions about game dimensionality are probably the most correct to stick
with. They can be argued up and down (absolutely no game can actually be
played in less dimensions than we exist in since we only exist in so many
dimensions - we might not need to exercise them to play the game but a chess
piece, a computer or any existing encoding of data that we have today requires
representation in 3 (or however many you think we have) dimensions - similarly
pretty much everything (everything, I think?) can be described in data that
can be expressed linearly so all games and the entire world can be said to be
1D. I think the fair middle ground is to try and adhere to the meaningful
definition of dimensions in the middle that actually lets us classify things
differently instead of saying that everything in existence is both 1D and
multi-dimensional.

~~~
tutfbhuf
Hmm. okay I understand that you still disagree but I don't get your point.

> So I think you can tactically play football and chess equivalents in 1D, but
> the actual movements required to execute the game still require three
> dimensions

I don't know what you mean by tactically. I never played football in 1D in my
life and I think no one ever has, except if you are referring to a computer
game or computer simulation. But I have played blindfold games without a
chessboard and without a computer.

> but you can't move your pawn forward on the board in 1D

you don't need a board to play chess. A chess board be it in 2D representation
on a computer screen or in 3D in real life is just a optional representation
of the chess game, but you don't need it.

> a computer or any existing encoding of data that we have today requires
> representation in 3 (or however many you think we have)

I think we most likely have (according to theories that are mathematically
sound) four non-compact dimension and seven that are curled up, so 11, but
obviously there's no proof for that.

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pmoriarty
I've enjoyed Alice Chess[1], which is played with two boards and on each move
a piece on one board goes "through the looking glass" to wind up on the
corresponding position on the other board.

Also fun was Suicide Chess[2], where the winner is the first to get all their
own pieces captured.

About 20 years ago, I found a book in The Strand which had collected something
like 300 chess variants... I'm sure by now there are many more.

[1] -
[https://en.wikipedia.org/wiki/Alice_chess](https://en.wikipedia.org/wiki/Alice_chess)

[2] -
[https://en.wikipedia.org/wiki/Losing_chess](https://en.wikipedia.org/wiki/Losing_chess)

~~~
shagie
Within 5d chess, there's a mode called "Timeline invasion". In this mode,
there are 2x 5x5 boards. On one board, you have BRKBN and five pawns, and I
only have five pawns. On the other board, I have BRKBN and five pawns and you
only have five pawns. These two boards are parallel dimensions that then
follow the rest of the rules.

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juped
This is a weird little game - regular checkmates are often not, because the
king can just escape back in time or across timelines, but threatening a
king's past self is pretty easy - it can't escape having been where it was.
And you only need one checkmate to win, because you have to make a move on all
boards where it's your turn (even if you have no pieces there - you have to
move one there!).

You can also give check with a king, because of the quirk that only "the
present" can threaten check. At least, I think that's why it works.

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samfriedman
Quite an interesting puzzle game, but it's not all that similar to chess given
the extra dimension. This means that a knight might move two spaces forward
and one back in time: a lot of patterns you may be used to seeing & responding
to in normal chess will need to be rethought or thrown out.

With that in mind it is a lot of fun to figure out new strategies and
patterns!

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mensetmanusman
The alpha go team is working with Chess grandmasters to determine which
variations to the rules of chess result in a larger state space with more
complexity.

They believe this will allow them to find a game that has more space for human
creativity (since most games now are very constrained in the first 40 moves or
so).

Would be cool to submit this game to see where it falls :)

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jrootabega
Damnit, now Neal Stephenson is gonna roll a new crypto standard based on this

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jelliclesfarm
[https://en.m.wikipedia.org/wiki/5D_Chess_with_Multiverse_Tim...](https://en.m.wikipedia.org/wiki/5D_Chess_with_Multiverse_Time_Travel)

~~~
jwilk
Non-mobile link:

[https://en.wikipedia.org/wiki/5D_Chess_with_Multiverse_Time_...](https://en.wikipedia.org/wiki/5D_Chess_with_Multiverse_Time_Travel)

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adrianmonk
The press kit section of the page says it has AI opponents. At first this
didn't seem remarkable to me since it's a standard feature of most chess
games.

But, how would that work? Would they have to create a new AI implementation?
An off-the-shelf chess AI presumably doesn't understand the best strategies
for multiverses. Unless there is some trick to apply an off-the-shelf AI to
this.

~~~
repiret
Off the shelf techniques for zero sum games of perfect knowledge would work
though. Minimax and Monte Carlo Tree Search and reinforcement learning from
self-play. Leela has been adopted to play both go and chess, I suspect it
would be practical to adopt it to play any game.

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forgotpwd16
I guess that's the Time Lords' chess variant. /jk

This is interesting but it will be nice if a short description was on site.

~~~
ggggtez
No, apparently timelords just play the Towers of Hanoi.

[https://www.bbc.co.uk/programmes/articles/3DHlYgfSdY2RlXkS2K...](https://www.bbc.co.uk/programmes/articles/3DHlYgfSdY2RlXkS2KwjtKK/the-
fourth-
dimension#:~:text=THE%20CURSED%20GAME,the%20completion%20of%20the%20serial).

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fctorial
Yeah, I is totally smart enough to play this.

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scubbo
This marks the first repost I've ever seen on HN, having been using it for
nearly seven years. Not bad going!

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bashallah
It’s only 5D if you are allowed +5 to -5 moves each move.

Your result in 3D would always be an approximate

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angel_j
Y'all are not going to grok this, but time is not a dimension.

~~~
malux85
In this context it is, it's defined as the bi-directional line between game
state transitions, and can be measured quantitively like any other spatial
dimension.

I'm talking specifically about time in the context of this game, which is what
this thread is about, not time in the universe.

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netsectoday
This is just the same as playing the computer and hitting "Undo" when you get
screwed until you find where it all went wrong. Then you play that new
timeline and can "Undo" again to create another timeline.

This is a cool way to visualize "Undo" in chess.

~~~
shagie
"Undo chess" is a single timeline that a (human) player can rewind to a
previous board state. Movements in time are constrained to moving the board
state. Pieces cannot move independently of the board state in time.
Additionally, you still play all the timelines that have been created.

In 5D chess, the knight moves two spaces in one dimension and one space in
another. In a 2d board, this is the description of how a knight moves. In 5d
chess, a knight can move one space back in time and two spaces in the Y
dimension on the board two one space back in time. That is fundamentally
different than Undo chess.

Additionally, this puts a new knight on the board timeline that is forked off
of the previous move - so there are now three knights.

Lastly, as pieces can move through time as well as space, one of the standard
wins is a piece that is attacking the king in the past. I had a game where I
moved the queen to the same file as the king (which was currently protected) -
it was five spaces away. I moved another piece, and then won as the queen was
now attacking the king five turns in the past. The timeline for that board is
[https://slack-files.com/T0VD96U9G-F01A45YRLTG-cf2d776bd3](https://slack-
files.com/T0VD96U9G-F01A45YRLTG-cf2d776bd3) . You can see that there is no
piece at [T-1, Y+1], [T-2, Y+2], [T-3, Y+3], ... until the king at [T-5, Y+5].

