# Random Co-Ordinate

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Kohlstech
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Joined: 11/03/2017

I am Creating a Game that is Played on a 30 x 30 Square Grid

I looking for Idea's on how to create Random Co-Ordinates that don't Get Repeated

I was rolling 2 x 30 sided dice, and then Re-Rolling if a Co-Ordinate had all ready been used, late game this turned out to be a lot of Re-Rolling.

The other Idea i had would be to have 900 cards with a different Co-Ordinates on them shuffle then draw from the pile. (That's a lot of Cards)

Just wondered if anybody had an other ideas or know of any other games that handle this kind of Mechanic.

Thanks.

Jay103
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Joined: 01/23/2018
Kohlstech wrote:I am Creating

Kohlstech wrote:
I am Creating a Game that is Played on a 30 x 30 Square Grid

I looking for Idea's on how to create Random Co-Ordinates that don't Get Repeated

I was rolling 2 x 30 sided dice, and then Re-Rolling if a Co-Ordinate had all ready been used, late game this turned out to be a lot of Re-Rolling.

The other Idea i had would be to have 900 cards with a different Co-Ordinates on them shuffle then draw from the pile. (That's a lot of Cards)

Just wondered if anybody had an other ideas or know of any other games that handle this kind of Mechanic.

Thanks.

The dice seem most obvious. Cards are ridiculous :) Well, unless there are two sets of 30, but that's basically dice.

So, this game requires the placing of random somethings on the grid even in the endgame when the grid is.. what, more than half full, I assume?

Maybe something like a rule that, when you land on a particular full space, you just move "vertically" on the board, wrapping around at the edge, until you hit an empty square? If the whole column is full, THEN you re-roll.

let-off studios
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Joined: 02/07/2011
Coordinate Dice

Use dice, combined with Jay103's idea of moving set spaces.

For example, with two six-sided dice: The faces of the dice range from -3, -2, -1, +1, +2, +3. One is for the x coordinate, one is for the y coordinate. Start at the place that was last used to mark the map.

Of course, greater numbers of sides on the dice indicate the potential for a greater spread across the grid with one throw.

Kohlstech
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Joined: 11/03/2017
A little more Description on

A little more Description on the game,Image a Traffic Grid of roads
Players Move Around the Board via roads.

But with the Random Co-Ordinates, The Co-Ordinate of that square,the Road is closed,now players have to find another Path Around.

So as the game Progresses the More Paths Becomes Blocked. The Harder it is to get to you goal.

Fri
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Joined: 09/06/2017
2 solutions

Solution 1: Have two sets of 30 cards. One with the numbers 1-30. The other with the "letters" on a-z and aa, ab, ac, ad. Then label your board like an expanded chess board

Draw two cards and you have a random coordinate.

Solution 2: Use the method from Flash Point. Assign each coordinate an arrow that points to a different coordinate. Then role two dice to pick a coordinate. If that coordinate is full then try to place the coordinate that it's points to. If that coordinate is full repeat the follow the arrow process until you find a spot that is not full. (Flash Point uses a red d6 and a black d8 to pick coordinates)

Kohlstech
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Solution 1: would result in

Solution 1: would result in the same method as 2 x 30 dice

Solution 2: Seems Interesting, I maybe able to Utilize this Idea.

Using 1-way Streets. Thank you.

Jay103
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Joined: 01/23/2018
let-off studios wrote:Use

let-off studios wrote:
Use dice, combined with Jay103's idea of moving set spaces.

For example, with two six-sided dice: The faces of the dice range from -3, -2, -1, +1, +2, +3. One is for the x coordinate, one is for the y coordinate. Start at the place that was last used to mark the map.

Of course, greater numbers of sides on the dice indicate the potential for a greater spread across the grid with one throw.

Well, that won't really work, will it?

First, there's a big difference in the design between a random spot out of 900, and a random spot out of 36 that are near the previous spot. Maybe the design supports it, but probably that's a big difference.

Second, if the issue is that spaces are filling up and he's trying to avoid lots of re-rolls, this doesn't address that. You have just as many re-rolls.

The one-way-arrow thing (solution 2) sounds okay.. that's basically a version of the one I suggested (in mine, all the arrows point north :) )

Fri
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Joined: 09/06/2017
More thoughts

@Kohlstech If you discard the cards after each pick you are guaranteed at least 30 rounds without overlaps. I am not sure if this is enough.

@jay103 I agree solution 2 is basically the same as what you said, but you managed to get your post out a little quicker then I did. (I had to remember how to embed images)

I also had another thought about this. The picking of coordinates seems to correlate roughly to road closure for construction or maybe traffic accidents. Instead of permanently closing the road I was wondering if you could close it for X turns . To do this you could add X cubes to the spot and remove one each round. That section is closed until all cubes are removed. This when a coordinate gets picked again, you simply add more cubes to it. It represents a delay in construction or another traffic accident. Just a thought.

Good luck with your game.

Jay103
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Joined: 01/23/2018
Fri wrote: @jay103 I agree

Fri wrote:

@jay103 I agree solution 2 is basically the same as what you said, but you managed to get your post out a little quicker then I did. (I had to remember how to embed images)

Well, yours is cooler if there's room to put little arrows. :)

ceethreepio
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Joined: 04/01/2019
I've got about 70% of an idea ...

Okay, so I think you can use a binary search partition to solve this ... I think you need about 11 coins, and a bag.

Algo:

1. Put all the coins in the bag.
2. Shake the bag.
3. Pull all the coins out of the bag, and place them heads up or down (as they came out of the bag) in a row.
4. Start by considering the entire board as the current partition of 30x30.
5. Divide the current partition and divide it into two equal partitions. E.g. 30x30 = Two partitions of 15x30.
6. Look at the first partition - Is there at least one space/co-ordinate left that is free and not taken?
7. Look at the second partition - is there at least one space/co-ordinate left that is free and not taken?
• If there are no spaces left on either partition, then the board is full.
• If there are only spaces left on either the first or the second partition but not both, discard the full partition and repeat from step 5 with the remaining partition.
• If there is space left on both partitions, look at the coin. If it is heads, take left partition, tails, the right.
• If the chosen partition has more than 1 space remaining, place the current coin in the bag. And repeat from step 5 on the current partition, using the next coin in the list. -- If the partition has only 1 space, you've found your random location.

30x30 -> 15x30 -> 15x15 -> 8x15 -> 8x8 -> 4x8 -> 4x4 -> 2x4 -> 2x2 -> 1x2 -> 1x1

It's a very 'computer science-y' way to solve this ... but I think it would work. It has the nice benefit of when you encounter a 'full' partition, you can simply ignore it and move straight on to the other side, meaning you need less coins to find a location the fuller it gets.

Nick

questccg
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Joined: 04/16/2011
Another idea...

Using the "chess-notation" (1-30 x 1-30), one player picks the ROW and the other player picks the COLUMN. This eliminates die rolling, adds a "competing" layer of strategy, and can create a "mini" area-control mechanic...

Obviously you must pick a ROW with at least one spot remaining. Or vice-versa with the COLUMN (at least one spot left).

Instead of RANDOM "luck" rely on STRATEGY and players decision making process. This is much simpler than most of the above solutions and adds more GOOD "complexity" to the selection process by making it NON-RANDOM.

Cheers!

Note #1: Variations of this could be SEMI-RANDOM where one player rolls 1d30 for the ROW and the other player PICKS which COLUMN he prefers. This is a HYBRID solution...

Note #2: Both the original and variant help reduce the risk of a RETRY. Like using the variation, you roll 1d30 and land up on a row with 1 COLUMN left. So naturally there is no choice in this case. But it's true the ORIGINAL idea of having 2 Players choose is the best since it GUARANTEES that there will be no loss time "re-rolling" anything.

Jay103
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Joined: 01/23/2018
Um Sure, as long as your game

Um

Sure, as long as your game is about placing these little pieces, and not about anything fun...

ceethreepio wrote:
Okay, so I think you can use a binary search partition to solve this ... I think you need about 11 coins, and a bag.

Algo:

1. Put all the coins in the bag.
2. Shake the bag.
3. Pull all the coins out of the bag, and place them heads up or down (as they came out of the bag) in a row.
4. Start by considering the entire board as the current partition of 30x30.
5. Divide the current partition and divide it into two equal partitions. E.g. 30x30 = Two partitions of 15x30.
6. Look at the first partition - Is there at least one space/co-ordinate left that is free and not taken?
7. Look at the second partition - is there at least one space/co-ordinate left that is free and not taken?
- If there are no spaces left on either partition, then the board is full.
- If there are only spaces left on either the first or the second partition but not both, discard the full partition and repeat from step 5 with the remaining partition.
- If there is space left on both partitions, look at the coin. If it is heads, take left partition, tails, the right.
- If the chosen partition has more than 1 space remaining, place the current coin in the bag. And repeat from step 5 on the current partition, using the next coin in the list.
-- If the partition has only 1 space, you've found your random location.

30x30 -> 15x30 -> 15x15 -> 8x15 -> 8x8 -> 4x8 -> 4x4 -> 2x4 -> 2x2 -> 1x2 -> 1x1

It's a very 'computer science-y' way to solve this ... but I think it would work. It has the nice benefit of when you encounter a 'full' partition, you can simply ignore it and move straight on to the other side, meaning you need less coins to find a location the fuller it gets.

Nick

Jay103
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Joined: 01/23/2018
You have the same problem of

You have the same problem of having to choose over and over again as it gets full (plus a hidden-information mechanic you have to add...)

questccg wrote:
Using the "chess-notation" (1-30 x 1-30), one player picks the ROW and the other player picks the COLUMN. This eliminates die rolling, adds a "competing" layer of strategy, and can create a "mini" area-control mechanic...

Obviously you must pick a ROW with at least one spot remaining. Or vice-versa with the COLUMN (at least one spot left).

Instead of RANDOM "luck" rely on STRATEGY and players decision making process. This is much simpler than most of the above solutions and adds more GOOD "complexity" to the selection process by making it NON-RANDOM.

Cheers!

Note: Variations of this could be SEMI-RANDOM where one player rolls 1d30 for the ROW and the other players PICKS which COLUMN he prefers. This is a HYBRID solution...

questccg
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Joined: 04/16/2011
You must have misunderstood

Jay103 wrote:
You have the same problem of having to choose over and over again as it gets full (plus a hidden-information mechanic you have to add...)

I think you fail to understand the solution: you MUST choose a NON-EMPTY ROW... Which means AT LEAST ONE (1) NON-EMPTY COLUMN. It's REAL players doing the choosing...

I don't see how there will be more than 2 CHOICES...!

Jay103
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Joined: 01/23/2018
questccg wrote:Jay103

questccg wrote:
Jay103 wrote:
You have the same problem of having to choose over and over again as it gets full (plus a hidden-information mechanic you have to add...)

I think you fail to understand the solution: you MUST choose a NON-EMPTY ROW... Which means AT LEAST ONE (1) NON-EMPTY COLUMN. It's REAL players doing the choosing...

I don't see how there will be more than 2 CHOICES...!

Oh, well if one player chooses row, and then other player chooses column afterward, sure, that would work. But that's also a huge change to the game's strategy.

questccg
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Joined: 04/16/2011

Jay103 wrote:
...Oh, well if one player chooses row, and then other player chooses column afterward, sure, that would work. But that's also a huge change to the game's strategy.

Alternatively you can use ONE (1) die roll (1d30) and then the Player chooses the COLUMN. Which is 50% random ... Yeah, having a PLAYER choose the ROW "ensures" that there are no "repeats" in terms of the selection mechanic...

But it's just a 1d30 roll in the variant. So you might need to roll it 1 (or may 5) extra times.

I agree the "strategy" is impacted ... but I think in a POSITIVE way. You're ADDING strategy to the game with a selection mechanic. Which sometimes may be limiting (only 1 column left in the row). Fundamentally that's the core of the issue: do you want RANDOMNESS or do you want to ADD a "layer" of strategy in the selection mechanic?!

Both are relatively simple... It just depends how the designer wants his game to play out...

questccg
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In relation to my own WIP

This is 100% an aside... (Read if you are interested)

Monster Keep (MK) my current Work-In-Progress (WIP) is also formulated around a "grid" (5x5 or 7x7). So I'm very in-tune with "strategies" with grids and the impact of mechanics on them... because I'm "in the trenches" so to speak.

Instead of using a "static" board (like 30x30), I am using a "dynamic" grid. Each game is DIFFERENT in that player's START with the "Nexus" card at the CENTER of the Keep... but it is rare that the "Nexus" is the center for the entire game. What I mean by this is player's ADD cards to the Keep and they form the shape dynamically.

This means that the "Nexus" could be in the CENTER, TOP-RIGHT corner, BOTTOM-LEFT corner or somewhere in-between. It VARIES.

BTW I'm not hijacking this thread... I just wanted to explain the SOURCE of my inspiration when it came to the OP. I've been playing with grids over the last 2 months and previously (before that too) with earlier iterations of the game.

So this is what I have been "involved" with in all its details for the last long while... Would make sense that I have some clue of what could/could not work.

Cheers!

Note: In MK... my primary source of inspiration was Tic-Tac-Toe! Obviously Tic-Tac-Toe is a much too simple game where mature players usually end the game in a Draw. With MK's dynamic grid ... there was only one (1) game that I thought was going to end in a TIE... But in the second to last turn, there was a choice to be made and in either spot, the result was a loss of Morale and therefore the loss of the game.

X3M
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Joined: 10/28/2013
Directional dice and a graph like map

For a random map in position AND random size. We always rolled a number of dice for the X and Y axis. We start from the previous location. And we simply went into that direction and skipped any filled position.
Of course at the end of one of the coördination, you go back to 1 and continieu to count.

First the X was done. Then the Y.

The result was that the new place would more often have a different X than the previous place.

Example:
A board is 6x6.
We use d6 for X and then for Y.
(If the board is 30x30, you use d30)
X5, Y4.
We fill that position.
Then we roll again.
X+3, Y+6. We end up on X2, Y4.
Then we roll again.
X+5, Y+1. We end up on X3, Y5.

Try to follow that to know what I mean.

Of course if an X is completely filled. You do Y+1.
Example: Y4 is filled on all X coördinates. So ypu look for an X on Y5.
Then make sure X is done first before you continu what you rolled for Y.

Good luck with your game.

ceethreepio
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Joined: 04/01/2019
Well, it depends ...

Jay103 wrote:
Um

Sure, as long as your game is about placing these little pieces, and not about anything fun...

Lol

In my defence, that wasn't a stated requirement in the OP. My understanding of the the original question was to provide a way to randomly select a unselected coordinate in a 30x30 grid, whilst:

1. Ensuring that there is little to no redundancy (e.g. that co-ordinate is full already, so is that one, keep rolling ...),
2. Doesn't use a lot of components (e.g. 900 cards)

My algo satisfies both of those requirements with random selection, and no redundancy. There wasn't any stated requirement for fun :)

Now, that might seem glib but it depends on the context. If this algo is only run, say, five times in the entire game, then its execution isn't a problem. If it's run five times a round, and there are 100 rounds, then it's going to be a pain.

Kohlstech
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Joined: 11/03/2017
Some Great Idea's, Gives me

Some Great Idea's, Gives me lots to think about.

A little More About the Game, This is a CO-OP vs the Game.

So Players start at Random Co-Ords, And are trying to collect 5 Goal Pieces that are also Placed on the Grid at Random Co-Ords, To win the game players must bring all the Goal Pieces to Another Random Co-Ords Goal Square.

(Block) the Random Co-Ords Locations, At the start of the game happens 3 times at the end of a Players turn, but events happen in the game that Increase the amount of Blocked Locations at end of a players Turn.

Thanks again for your inputs.

Jay103
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Joined: 01/23/2018
Sort of a version of

Sort of a version of Forbidden Island, with a much bigger grid and blockades instead of sinking. Sounds like it could be fun.

questccg
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Joined: 04/16/2011

Kohlstech wrote:
A little More About the Game, This is a CO-OP vs the Game.

Well if this is the case, why not one (1) Player chooses the ROW and writes down "secretly" three ROWs of their choosing. At the same time, another Players chooses the COLUMN secretly too!

The the FIRST pair is revealed... If that location is "invalid" (by whatever reasons in your game), the SECOND pair is used. Again similarly IF they cannot use that location the THIRD pair is used.

This could introduce "hidden information" from the two (2) Players doing the tile choosing. This could be another "interesting" selection mechanic which could be GOOD for a "CO-OP" game!

Cheers...

apeloverage
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Joined: 08/01/2008
For true randomness, without

For true randomness, without re-rolls, you'd have to use cards or chits.

Kohlstech
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Joined: 11/03/2017
Thanks for all your help

Thanks for all your help Everyone

This is the Solution I am Going with:
Which is a combination of Peoples idea's

I am Going to stick with the 2 x D30.(1 blue,1 RED for X,Y Axis)
I am going to add a D6 to the mix, With 1 of each direction and 2 x Players choice of Direction.

Using the Method of Roll 2 x D30 get location if Location is already Used, Roll D6 follow that Direction to the first available Empty Space.Also Using the Method if at edge of Board Wrap around to other side.

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