Null Field vs. Fortune

[Bigger-than-Jesus]

In fantasy, there's a rule that allows re-rolling failed to hit rolls in HtH(hatred). Chaos has a suit of magic armour that forces your enemy to re-roll successful to hit rolls in HtH. In that case you re-roll the misses, then re-roll ALL hits, regardless of it's already been re-rolled. I'd apply that here too.

And you would be wrong. You can never re-roll a dice more than once. Never. Like model attributes going over 10, it cannot happen.

Funnily, that solution came from the old rules query bit in a WD around the time issue 300 was released, in the community section. Me and my mates used that as inspiration tosort out stuff like that among ourselves.

[Somar]

so, does anybody really think this could happen?

 

eldar player: i will now make the saves for my seer council, because of the 2 powers in effect i will just roll these dice once and apply the results.

SM player: no sorry, you cannot do that, you have to roll them once, then pick all of them up and roll them again, ignoring the 1st roll...

(the choice of a reasonable person and a moron has nothing to do with their choice of armies and is purely hypothetical)

eldar player: you are serious, huh? ooookaaaayyy...

[Koremu]

so, does anybody really think this could happen?

 

eldar player: i will now make the saves for my seer council, because of the 2 powers in effect i will just roll these dice once and apply the results.

SM player: no sorry, you cannot do that, you have to roll them once, then pick all of them up and roll them again, ignoring the 1st roll...

(the choice of a reasonable person and a moron has nothing to do with their choice of armies and is purely hypothetical)

eldar player: you are serious, huh? ooookaaaayyy...

I've met people like that. Just nod, smile and back away slowly.

[Morticon]

YupYup yup.

 

Just to lend support to the people that are (correctly) saying these powers are not in conflict.

 

1. Roll the dice.

2. Re-roll both your failed armour saves (fortune) and your passed ones (null zone).

3. Rule for not rerolling dice twice kicks in and you keep that result.

[DevianID]

In my opinion, you should simply roll the second set and ignore the first set. Rolling pointless dice is just frustrating and time consuming--you dont roll the bolters to-hit versus a land raider, cause its pointless, right? My only issue is that you have to tell your opponent before doing anything, no matter how you play it, because one of you are bound to be contrary.

 

For example, assume you always play that the first roll doent count. You roll what you assume are the second set of saves, and roll 4 6's. Your opponent then tells you to reroll, and now you have an argument, as you didnt explain how the powers cancel the first roll so you didnt bother rolling them.

 

Next turn, you roll 4 1's, and pick up all the dice to reroll. Your opponent then tells you that you have to keep those dice cause thats what you wanted originally. You then have another argument because he gave you crap the first time around, thus you were gonna do it his way, but now he wants you to do it your way (and you assume its because your opponent wants you to keep your failed saves).

 

Its a pain in the butt to have to clarify with every single opponent. You only have to forget once in a tourney to make your opponent attack you as a cheat.

[Somar]

very good point, communication is the key here i guess. talking about this subject blows the whole issue a bit out of proportion, i think the people that get too worked up about it once you are face to face with them are few and far between.

[shatter]

.

 

Or you can save time and just do the one roll.

.

 

what he said

[Seahawk]

Really though, how much time is truly saved? About 5 seconds, tops. To complain so much about such a minute amount of time is frankly ridiculous. It's always good to play honestly and by RAW by rolling all the dice twice. No confusion, no mess.

[IanV]

But what if it's proven mathematically doing the re-rolls wouldn't matter? Just to prove w/o a shadow of doubt that you don't have to.

 

(Skip this if you hate math)

 

Let's just say:

 

P = passed save

F = failed save

 

The possible outcomes would be:

 

_____1st roll _________re-rolls due to null

_______________________________PP____________.

_________P___________________________________.

_______________________________PF____________.

 

_____1st roll__________re-rolls due to fortune

_______________________________FP____________.

__________F__________________________________.

_______________________________FF____________.

 

With the initial outcomes being P and F and then branching out to PP, PF, FP and FF, giving us four pairs.

 

Now let's say the probability of a pass is A, it will follow that the probability of a fail is (1-A).

The probability of each four pairs would just be their pass/fail products. Which gives us:

 

________PP________________________PF_________.

________(A)(A) = A^2___________(A)(1-A) = A - A^2__.

 

________FP________________________FF_________.

________(1-A)(A) = A - A^2_______(1-A)(1-A) = 1 - 2A + A^2.

 

Now lets add the ultimately successful saves, PP and FP = [A^2] + [A - A^2] = A

Now lets add the ultimately failed saves, PF and FF = [A - A^2] + [1 - 2A + A^2] = 1 - A

 

We could stop here because we did declare that A is in terms of probability not in terms of number of outcomes but just to be sure, we have to follow the strictest def'n of probabailty. Prob = (successful outcomes)/(total outcomes)

 

So Prob of a P is: A/[A + (1 - A)] = A/1 = A

And Prob of F is: (1- A)/[A + (1 - A)] = (1- A)/1 = (1- A)

 

Alright, we're almost done, just an example:

 

Let's use a 3++ for a 2/3 chance of success (and 1/3 chance of failure). Let's go back to the pairs:

 

_______PP________________________PF_______.

_______(2/3)(2/3) = 4/9________(2/3)(1/3) = 2/9__.

 

_______FP________________________FF_______.

_______(1/3)(2/3) = 2/9________(1/3)(1/3) = 1/9__.

 

These are now the probabilities of each pair. Now let's apply Prob = (success)/(total) again and let's just cancel out the denominators for simplicity.

 

Prob of P = (4 + 2)/(4 + 2 + 2 + 1) = 6/9 = 2/3 which is what we started with...

 

 

In short, don't do the re-rolls. :P

 

EDIT: Had to line up the columns using underscore. Spaces are ignored?

[Banville]

Yeah but if you were to go on mathemantical probability, why bother rolling anything? Just take it that six marines rapid firing bolters at another six marines will result in eight hits, resulting in four wounds, resulting in one dead marine. Why bother using dice, as maths will always predict what is definitely going to happen. ;)

[IanV]

*nods...*

 

*smiles*

 

*backs away slowly*

 

Just kidding. Math CAN predict it. I'm sure all of us use some bit of math in planning our tactics. Lot's of ones and sixes are extremes but the general behavior of the rolls still fall under an average. Take it with a grain of salt of brother. If you don't find this info useful then feel free to roll away everytime.

[ShinyRhino]

Ummm, you'd do the rerolls because the rerolls COULD benefit either player.

 

Let's say the Eldar player needs to make 5 saves. He rolls them: three pass, two fail. He rerolls the three passes because of Null Zone. Those three now fail! Hurrah! The Eldar player now rerolls the two failures, due to Fortune. One passes. Hurrah!

The rerolls result in the Eldar player failing four saves, instead of two. The End.

 

Roll the damn dice.

[IanV]

Alright, I clearly haven't put my point across well enough.

 

I won't use any equations this time.

 

You roll a set of dice. But due to the effects of null(re-roll the P's) and fortune(re-roll the F's) you have to pick up the whole set and re-roll them, disregarding the first results.

 

You roll a set of dice => it doesn't matter, pick them up and roll again. :P

 

That's the point of a lot of our fraters, the two powers cancel each other out.

 

Yes, I also see some of your points:

 

It doesn't take long

 

- Yes, like Seahawk said, maybe 5 seconds tops. Or God forbid, you roll your dice, groups them into P's and F's; then re-roll the P's and F's; then group them again into ultimately P's and ultimately F's. Seems like a lot of effort for a pointless technicality to me.

 

It's what the rules say

 

- Yes, it's what the rules, and I can't really argue with that... And if you choose to argue this way, then you win. But it still stands, you're wasting a set of dice rolls because you're just going to disregard the first roll anyway.

 

@Shiny: Hey bud. Uh sorry no. Re-rolls benefit a player if you only roll a subset of dice (ex. LoH - Chap and the unit he's attached to re-roll all failed (and only failed) rolls to hit). And you can't really use just one possible set of outcomes to get an idea of probability. You have to consider everything. What if the eldar player again passes all his initially successful saves and this time passes all his initially failed saves? Just one outcome in many.

[ShinyRhino]

@Shiny: Hey bud. Uh sorry no. Re-rolls benefit a player if you only roll a subset of dice (ex. LoH - Chap and the unit he's attached to re-roll all failed (and only failed) rolls to hit). And you can't really use just one possible set of outcomes to get an idea of probability. You have to consider everything. What if the eldar player again passes all his initially successful saves and this time passes all his initially failed saves? Just one outcome in many.

 

Just one outsome in many, correct. But that one outcome benefits the Marine player. And another might benefit the Eldar player. The game mechanics tell you to do the rerolls, so do them. You'd spend more time arguing the statistics of possible pass/failure benefit equations at the table than it would take to group those two sets of dice and roll them.

 

EDIT: Ohhhh, wait. I see what you're saying here. You have to reroll ALL the dice anyways because both rules are in effect. The oddsof hitting that 5+ invulnerable don't change due to the smaller subset or larger. It's always that 33% chance. I'm a dummy. Now I look the fool! Serves me right for posting while cranky IRL. :P

[IanV]

Hehe, no prob bud. And no you don't look foolish, been there before. Was angry at a coworker and ended up unleashing a less than tasteful rant on my manager. :P

 

EDIT: Oh wait... it means we both look foolish! doh! :)

[OwlandMoonGuy]

Alright, I clearly haven't put my point across well enough.

Very well put and after you went through all the trouble it seems obvious now afterwards.

 

So here’s my equation:

Rerolling all the required rerolls = canceling each other out = the same damn difference. ‘Nuf said.

 

The administratum offices of Kairos the Fateweaver (OoE; Oracle of Eternity) thanks you but since he knew your answer before you gave it he therefore takes back his appreciation before he gives it in the first place.

 

Cheers, -OMG

[Sternguard sergeant McColl]

why not just use the psychic hood when he tries to cast fortune, nullify it and then cast null? I can't see how this wouldn't work and you come out on top.

[Grey Mage]

why not just use the psychic hood when he tries to cast fortune, nullify it and then cast null? I can't see how this wouldn't work and you come out on top.

Because the newer psychic hoods dont always work each and every time.

 

And the eldar player will just as likely make you roll your test on 3d6, and take perils of the warp on 12+.