Some (Corrected) Spellcasting Stats

[Ormly]

Thread Necromancy isn't my practice. And my original post was so badly incorrect due to a bad copy/paste that they were worse than useless. But apparently Google has decided that this is the place to bring you if you search for "AoS Unbinding Statistics." So read the below, and ignore the OP.

 

Edited August 6, 2022 by Ormly
Massive Corrections

[Dogmantra]

I'm curious about your methodology because these results seem very strange to me.

Unless I'm mistaken, a CV4 spell should always be easier to cast than a CV7 spell. Let's break it down into the possibilities, let's call the CV4 spell Spell A and the CV7 spell Spell B

- Your roll is greater than or equal to 7, and greater than or equal to your opponent's unbinding roll (success for both spells)
- Your roll is greater than or equal to 7, but your opponent's roll is greater than yours (failure for both spells)
- Your roll is greater than or equal to 4, but less than 7, and also greater than or equal to your opponent's unbinding roll (success for Spell A, failure for Spell B)
- Your roll is greater than or equal to 4, but less than 7, but your opponent's roll is greater than your roll (failure for both spells)
- Your roll is lower than 4 (failure for both spells)

As you can see, this is every possible outcome, and Spell A succeeds in every situation that Spell B does, and additionally one extra situation. I don't have the exact probabilities to hand for each of these situations, but there's no way for the number of situations in which Spell A succeeds to be less than Spell B.

I also did the maths with a handy program called McDie, which is built to simulate complex dice interactions.

This is the test I ran. It rolls 2d6, adds it up and performs two checks: that it's greater or equal to than the CV (in this image 4), and that it's greater than or equal to a second roll of 2d6 (the unbind roll). The network then outputs this to a graph which shows the % of the time that both of these are true, and the % of the time at least one is false. This is achieved by simulating 100 000 repeats of the rolls, so the numbers vary very slightly. An output of TRUE means that the cast was successful, and FALSE means it failed.

For CV4, we can see that you successfully cast vs an unbind around 55% of the time.

Editing to CV7, we get this result:

And you succeed somewhere around 45% of the time.

Here's a graph of the chance to succeed for all casting values vs an equally powerful unbind attempt. The leftmost bar is a quirk of the program (the actual methodology behind this chart is that it shows the chance of the output being >= the x axis, with the output being either the casting roll if it was greater than the unbind, or set to 1 if it was less than the unbind roll because as far as I can tell this program doesn't have a way to do exactly what I want)

Or if you prefer actual numbers because it's a bit hard to read. Again this is based on 100 000 rolls rather than actual calculations so it's quite accurate but the exact percentages will vary very slightly.

CV	Chance
2	55.525
3	55.455
4	55.004
5	53.66
6	50.578
7	44.904
8	35.174
9	25.039
10	15.74
11	8.109
12	2.761

[yukishiro1]

Yeah the math in the original post seems quite dramatically off to me. I wonder if it was done on the mistaken assumption that to dispel you only need to roll higher than the CV, not the actual roll? 

 

 

Edited May 6, 2022 by yukishiro1

[Neil Arthur Hotep]

10 hours ago, Dogmantra said:

 

I have done this math before and this looks pretty much right to me.

Honestly, realizing that if you have to go through an unbind your odds of successfully casting a spell are always at best a coin flip has put me off of bringing wizards pretty strongly. Especially the one cast no bonus wizards that I would only take for their spell. Upwards of 100 points (frequently more like 130) for a 50% chance to trigger an ability is just not that enticing. On the other hand, all those it has raised the value of all those Destruction wizards a bit for me. After all, figuring in unbinds. a CV 7 spell is not actually that much less likely than a CV 4.

But given that unbinds change the casting math so significantly, I tend to try to bring at least one wizard. Just not for their flashy warscroll or lore spells, usually. Rather, I only want them for the unbind and to cast Mystic Shield every once in a while. Of course, when wizards with good casting bonuses or extra casts are available, that changes things quite a bit.

[yukishiro1]

Magic in WHFB/AOS has always been a bit of a weird feast and famine kind of thing where it tends to be of very limited value if you don't go in hard. It's not as bad as old WHFB where you could win the game with one supercharged spell, but the basic structure where small wizards of limited power are largely neutered has remained, and the result of that is that you either need to take supercasters or just take so many casters that you can overwhelm their number of unbinds to have a reasonable chance of getting stuff off.

40k actually does this way better, largely because psychic powers are (terrible balance snafus aside) less powerful, but also a lot more reliable to get off because psykers aren't as ubiquitous, deny range is small enough that it can often be played around, and you can always reroll a cast if you really need it.

Competitively AOS is actually in a pretty good place re: magic doms right now in that Seraphon is the only dominant faction at the moment that is really oppressive re: shutting down your opponent's magic. So even normal wizards can be fairly useful. But that wasn't the case throughout most of AOS 2 and I wouldn't be surprised if it becomes less the case in AOS3 too as we get new Lumineth and Tzeentch books. 

If it were me I'd reduce unbind range to w/in 12" of the caster or the target, and change Slaan unbind to only allow the first unbind to be board-wide. Suddenly you don't need to be a magic dom to cast as long as you position well, and casting becomes much more reliable generally and more about smart play and less about just rolling dice and seeing if the RNG god blesses you. 

Edited May 6, 2022 by yukishiro1