"Converting odds to dice" Topic

so i was looking at my copy of SSI's old computer wargame 'Battlecruiser' and what is cool about this old game is that in the rules they actually provide the formulae for calculating hits and all the modifiers that apply, which means one could convert it to the tabletop possibly

that being said, the determination of whether a shell hits the target is based on odds – and the modifiers can reduce the odds to the limit if 1/230 at worst. – my question is can odds be converted somehow to dice rolls?

say if for example, the calculated odds to hit came up as 1/93 or 1/131 or something like that – how could one translate that to dice? is this even possible, or would there be a better system that could model odds?

Do you mean odds of 1:230 (ie 1 hit for every 230 misses) or that 1 in 230 shots is a hit ?

It makes very little difference at such low odds but the difference between the two gets greater as the odds get better.

Maybe the simplest solution would be to use a virtual die roller on your phone or computer. You can just tell it you want to roll a 230 sided die, or whatever your need may be for an individual roll.

Something like the "non-conventional die roller" on a site like this:
link

1:230 is really close to rolling three sixes on three dice (1:216).

thanks for those suggesstions – sorry i was trying to link this topic to also the ww2 naval general discussion board but failed
so i had put it there as well and got helpful replies too

TMP link

- the idea of 3d6 was brought up there and it could be a good solution,

but now i am thinking even just using one d100 could be fine – anything like 1/230 odds is could just be rolling a 1 – and if i wanted to get more granular then it could be some additional dice

but i think fitting it to 3d6 or using a D20 and making some simplifications could be best

The easiest way to do this is to create a table with the odds to get a particular value, and see how that matches the probabilities that you want to achieve

Here's an example I did, thinking about activation

Roll number or better

D6
2 : 0.83
3 : 0.67
4 : 0.5
5 : 0.33
6 : 0.17

D10
2 : 0.9
3 : 0.8
4 : 0.7
5 : 0.6
6 : 0.5
7 : 0.4
8 : 0.3
9 : 0.2
10: 0.1

2D6
3 : 0.97
4 : 0.92
5 : 0.83
6 : 0.72
7 : 0.58
8 : 0.42
9 : 0.28
10: 0.17
11: 0.08
12: 0.03

For more than one die being rolled, it's really non linear so you might want to graph it as well

As commented, a d10 or d20 makes it pretty easy to map probabilities onto a die roll

John

Very important to remember that the moment you use more than 1 die you are not getting linear odds, so 3x1 on 3d6 is 1:216, but there is no way to get 2:216 as a score of 4 has a probability of 3:216. Given most of these numbers are educated guesses I'd recommend working them all out as percentages and using d100, it is highly unlikely to impact a specific game.

From a game design perspective I rarely worry about anything that happens less than 5% of the time as it isn't worth the trouble. If you need it as a potential special event just roll a D100.
My 2¢

Joe