Fractional odds and rounding

[Courtenay]

I do not understand how the rounding rules work in conjunction with the fractional odds rule and the 2d10 table.

Here is a specific example: A side is attacking in snow, and has a single winterized division. (And maybe some corps, but those are integers, and I understand integers.) The winterized division has an odds modifier of +0.5.

For the sake of argument, say that all other modifiers (odds, disruption, other pluses and minuses, etc) give a final die roll modifier of +7.75.

What is the effect of the winterized division? Does it simply add .5 to 7.75, giving a final die roll modifier of +8.25, or is 1/2 rounded up to one, giving final die roll modifier of +8.75?

As near as I can tell, the fraction rule applies (2.6), so the final result should be 8.75. However, I notice that MWiF does not do this for HQ support, a reorganization value 3 HQ adds 1.5, not 1.5 rounded up to 2.

So, does anyone know what the rule is?

[Dabrion]

When playing with 2D10 and FO you dont round at all. You retain all fractions until the final drm (including the fractional part) is fixed. In your case you stated +7.75 and get a +0.5 for a winterised division in snow ontop, that adds to +8.25.

This means you have a guaranteed +8 attack. Now you look at the first digit of the fractional remainder [2] (no rounding to 8.3 or the like), to get a 20% chance (roll of 1 or 2) on a +9 attack instead.


p.s.: might find this usefull: https://docs.google.com/spreadsheets/d/ ... id=3906537

[Courtenay]

Thank you.

[paulderynck]

Two clarifications here:

1. In RAW7 and MWiF, there is rounding only for point 5 and up of the factors attacking. FREX you invade a forest hex with a 5 Inf, supported by a 5 ground support and 5 shore bombardment. You have 2.5 + 2.5 + 2.5, rounded to 8 attack factors. It has been successfully argued that you shouldn't round up the attack factors when playing fractional odds, but that is not how RAW7 nor MWiF operates.

2. MWiF computes and tests the fractional odds modifier to three decimal places. For the odds plus mods, any fractional amount beyond the third decimal place is truncated. You'd have to ask Steve if the random number generated is rounded or truncated, but only the three decimals are reported to the players and compared with the fractional amount.

[brian brian]

also a note … with fractional odds and 2d10, on a +8.2 attack, you quickly forget about the idea of rolling a dice to see if you can get a 1 or a 2 and then get a +9 attack. You just roll three dice at once, with one color for the fractional chance, and a pair of the same color for the attack roll.

everything speeds up. I can't recommend Fractionals enough, but they are resisted sometimes.