# Dice roll vs. coin flip

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ReluctantPirateGames
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Joined: 09/27/2011

I've been designing a small skirmish game for a little while now, and have come upon an interesting dilemma. Without going into too much detail, it's a tabletop miniatures game played on a square grid (think Heroclix minus the clicking and the time commitment). During your turn all of your units can move and attack once in any order. The attacks are written on accompanying cards, and this is where my problem lies

Currently attacks are structured like this:
Slash (Melee, Push-1) 2 - 4 - 5 - 5 - 7 - 10
If the target of this attack has taken damage this turn, roll +1

In this scenario, the numbers above the description would correspond to the roll of a d6. This way I could weight attacks by character, not just with the bell-curve of a pair of d6's plus a set attack value. To me that seems more natural than every character having identical attack curves, just shifted up or down. But I recently came upon the idea of two coin flips. The same attack would look like this:
Slash (Melee, Push-1) 3 - 5 - 10
If the target of this attack has taken damage this turn, 1 auto-head

The four attack values in this case would be double tails - one and one - double heads. The weight on the middle attack would be 50%, so it could be considered the usual value, while the other two are a failure and a critical hit. "Auto-head" means that only one coin is flipped and the other is presumed heads. Anyhow, I'm not sure if this idea is good or just fun to think about. It would certainly be somewhat unique. Attached are some graphics for the "miniatures," which at this stage in testing are just paper dolls. This isn't really relevant to the mechanical issue, but it could be helpful in getting a sense of the game as a whole.

ontheplus
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Joined: 10/23/2011
Attack Curve

I like the concept of the dice curve.

But, with 2 coins (2d2), I like the visuals of a 2x2 matrix. Taking it further, you can even do a 3d2 using the binary system with a value range of (0-7)

pelle
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Joined: 08/11/2008
Yes, why not, but on the

Yes, why not, but on the other hand it is a bit gimmicky since you could achieve the same effect by using a single d4 or d6 (just organize the list of possible results a bit differently). But coin-flipping sounded quite elegant in that case you only had to flip one in some cases.

SLiV
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Joined: 10/21/2011
I would go with the dice.

I like the coin flip, it definitely simplifies it. Adding a third coin would render a 17% - 33% - 33% - 17% ratio. Perhaps something to toy with. I wouldn't go further (7% - 25% - 38% - 25% - 7%, meh).

But then again, I'm not quite sure. I'm personally more fond of rolling one dice than flipping two coins. The idea that different units can have different values attached to the sides of the dice, intrigues me just as much as the coins, to be honest.

I would go with the dice. I think it would allow for more interesting mechanics (e.g.: a 0 - 0 - 0 - 0 - 5 - 9 attack).

Yamahako
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Joined: 12/01/2010

One thing I find interesting from a game production perspective - is the seriously low cost of pennies :-)

if you "threw" pennies instead of flipped them (say into a box) you could get a good curve quickly and it would cost a lot less than standard dice :-)

I think my quotes for a standard 6-sided die have been in the 0.14 cent range for quantities of 2500... 5 pennies gives you a 6 sided die...

ReluctantPirateGames
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Joined: 09/27/2011
It's funny that you started

It's funny that you started listing probabilities. I always make excel files with all my probabilities for any game. And you're right, going to a fourth coin starts getting a bit annoying. And really, a third coin just returns you to the d6 system. A 3 coin system of 2-5-6-10 is identical to a d6 system of 2-5-5-6-6-10. This idea has definitely taken hold in my mind, I just worry that it is more gimmicky than useful. This sort of becomes the deeper argument of "is originality its own reward?" Functionally, a d6 is perfect. But will the game be "better" if I take it in a unique direction?

SilentFury
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Joined: 10/23/2011
With a d4 or a d8, you can

With a d4 or a d8, you can get the exact same probabilities as two coin flips on a die (25% both heads, 25% both tails, 50% one each vs. 25% roll 1, 50% roll 2 or 3, 25% roll 4), and rolling one die is simpler and easier than flipping coins (coins aren't as easy to see the results of or to handle as a die, as they're harder to pick up and you need to put them in a specific hand position for flipping.)

So the way to get a bell curve on a single die is to just use more of the numbers in the center for your attack results. You could have a smaller 3-5-10 damage scale by doing that. Roll a 1 - low damage. Roll a 6 - high damage. Any other number is average damage.

SLiV
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Joined: 10/21/2011
Mind the probabilities.

Yamahako wrote:
5 pennies gives you a 6 sided die...
That's not entirely true, since the probabilities are off.

The beauty of a sixsided die is that every side has an equal probability (1/6), so the probabilities of 1|2|3|4|5|6 are 17%|17%|17%|17%|17%|17%.

But when throwing 5 pennies, the probabilies of 0|1|2|3|4|5 are about 3%|16%|33%|33%|16%|3%, because out of a total of 32 possibilties, only 1 renders 0, 5 render 1, 10 render 2, 10 render 3, 5 render 4 and only one renders 5.

ReluctantPirateGames wrote:
And really, a third coin just returns you to the d6 system. A 3 coin system of 2-5-6-10 is identical to a d6 system of 2-5-5-6-6-10.
Well, not quite.

Because when I said

SLiV wrote:
Adding a third coin would render a 17% - 33% - 33% - 17% ratio.
I was mistaken.

There are a total of 8 possibilities, 1 to get 0, 3 to get 1, 3 to get 2 and 1 to get 3. Therefore, the ratio should be 13%|38%|38%|13%, which is not identical to 1|2|2|1 (but to 1|3|3|1).

Maaartin
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Joined: 05/15/2011

ReluctantPirateGames wrote:
And really, a third coin just returns you to the d6 system. A 3 coin system of 2-5-6-10 is identical to a d6 system of 2-5-5-6-6-10.

As already said, it's not. It's equivalent to a d8 labeled 2-5-5-5-6-6-6-10.

ReluctantPirateGames wrote:
This idea has definitely taken hold in my mind, I just worry that it is more gimmicky than useful.

In many games, the exact probabilities do not matter much. In order to find out the difference between a probability of 16.666% and a probability of 12.500% you really need quite many repetitions.

There are some exceptions: Sometimes the game needs some probabilities to be nearly the same, but that's just because the rules' designer counted on it. Starting with a different dice/coin/whatever, other rules could be invented which would lead to nearly the same game.

All in all I think playing with the probabilities doesn't bring much. But I'm surely biased as I hate randomness in games (except for some very moderate cases).

ReluctantPirateGames wrote:
This sort of becomes the deeper argument of "is originality its own reward?" Functionally, a d6 is perfect. But will the game be "better" if I take it in a unique direction?

I don't think any probability distribution can improve anything. You may need 10 possibilities which is a good reason for switching to d10. You may feel that d8 rolls better than d6, so go for it. You may have already coins in the game and want to reuse them for flipping, that's fine. I personally feel that paying too much attention to the probabilities may lead to inventing a complicated version of Ludo only.

kos
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Joined: 01/17/2011
Consider the physical

Consider the physical aspect of coin-flipping in a game.
If it was a few coins occasionally, it wouldn't matter. But I think I would get annoyed at flipping many coins repeatedly throughout the game. Dice are just so much easier to manipulate (except d4's and anything bigger than a d12).
I'm not opposed to randomisation per se, but for games with randomisation I want it to act naturally without interrupting the flow of the game.
That said, if coin flipping was integral to the theme of the game it would make sense. For example, consider a game of conflict between the forces of light and dark, or chaos and order, or red and blue. So the coins represent not "success vs failure" but "success for red vs success for blue". [Hmm... I should trademark that name before somebody else steals it... I'll call it Red Against Blue... or... Red Opposing Blue... or...]
Just my 2c with some digression.

Regards,
kos