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Hi everyone,

I've done some quick calcs based on activating psychic powers on 4s, the number of dice rolled and the risk of perils that go with it.


Looking for one 4 to activate: (warp charge 1)

Number of dice rolled) Probability

1) 0.500
2) 0.750
3) 0.875
4) 0.938
5) 0.969
6) 0.984
7) 0.992
8) 0.996
9) 0.998
10) 0.999


Looking for two 4s: (WC 2)

1) 0.000
2) 0.250
3) 0.500
4) 0.688
5) 0.813
6) 0.891
7) 0.938
8) 0.965
9) 0.980
10) 0.989


Looking for three 4s (WC 3)

1) 0.000
2) 0.000
3) 0.125
4) 0.313
5) 0.500
6) 0.656
7) 0.773
8) 0.855
9) 0.910
10) 0.945


And Chance to Peril

Number of dice rolled) Chance to peril with 2 or more 6s

1) 0.000
2) 0.028
3) 0.074
4) 0.132
5) 0.196
6) 0.263
7) 0.330
8) 0.395
9) 0.457
10) 0.515

It would be great if someone could indepenently check to see if their figures agree

Also, if anyone fancies adding their Deny the Witch probabilities, that would also be very welcome



As one would expect, the figures show that WC1 powers only need 2 dice to have a good chance (75%) to be manifested, with a negligible chance to peril. You're going to want 4-5 dice to activate WC2 with a 20-25% chance to peril and WC3 needs about 7 dice and carries with it a 1/3 chance to peril.

Clearly it will depend on what the power in question does to decide if it's worth the risk.

I wonder how do upgrades that grant re-rolls of failed psychic tests, like a Spell Familiar or the Balestar of Mannon, work with the probabilities of casting a power.

Also waiting to see if Eldar Ghosthelms are FAQed. If unchanged, Farseers will be in good shape to cast without fear.

 SarisKhan wrote:
I wonder how do upgrades that grant re-rolls of failed psychic tests, like a Spell Familiar or the Balestar of Mannon, work with the probabilities of casting a power.

Chance to Pass with re-rolls = Chance to Pass Normally + (Chance to Fail x Chance to Pass Normally)


It looks like armies with only 1 level 1 psyker will almost always have a very good chance to manifest 1 power per turn and often 2.

Armies with many psykers will have a reduced chance of successfully manifesting all of their powers each turn, but can focus on the important powers and optimise their risk/benefit management.


Automatically Appended Next Post:
All in all, the new Psyker mini-game seems pretty fair and requires the player to use their brain a bit. Much more tactical psykers in general.

Non-psyker armies are a bit nerfed vs. psyker-heavy armies.

 pocketcanoe wrote:

 SarisKhan wrote:
I wonder how do upgrades that grant re-rolls of failed psychic tests, like a Spell Familiar or the Balestar of Mannon, work with the probabilities of casting a power.

Chance to Pass with re-rolls = Chance to Pass Normally + (Chance to Fail x Chance to Pass Normally)


It looks like armies with only 1 level 1 psyker will almost always have a very good chance to manifest 1 power per turn and often 2.

Armies with many psykers will have a reduced chance of successfully manifesting all of their powers each turn, but can focus on the important powers and optimise their risk/benefit management.

Thanks, I have managed to figure that out just moments ago. You see, I'm a linguist, so my math skills are a lil' bit rusty.

Means that my Sorcerer with the Balestar has a 75% chance to cast Prescience with 3 dice and 90.2% chance with 4 dice. Fair enough.

Just google 'dice pool probability' and you will find several online tools which do all the hard work of calculating the odds for you.

As for the probability of rolling perils on rolls which trigger on any double, if my calculations are correct they are pretty bad...

2 dice: 17%
3 dice: 44%
4 dice: 72%
5 dice: 91%
6 dice: 98%

Seven or more dice is 100% chance of PotW, since it's impossible not to roll two numbers the same with seven six-sided dice.

That puts a massive damper on any plans to start conjuring daemons with anything other than daemons. All the WC 3 powers pretty much require you to take perils before getting your daemons, so most psykers are only going to be able to call in one unit before they are more likely to kill themselves than succeed in a summoning.

 Perfect Organism wrote:
Just google 'dice pool probability' and you will find several online tools which do all the hard work of calculating the odds for you.

As for the probability of rolling perils on rolls which trigger on any double, if my calculations are correct they are pretty bad...

2 dice: 17%
3 dice: 44%
4 dice: 72%
5 dice: 91%
6 dice: 98%

Seven or more dice is 100% chance of PotW, since it's impossible not to roll two numbers the same with seven six-sided dice.

That puts a massive damper on any plans to start conjuring daemons with anything other than daemons. All the WC 3 powers pretty much require you to take perils before getting your daemons, so most psykers are only going to be able to call in one unit before they are more likely to kill themselves than succeed in a summoning.

Ah, more useful numbers. Cheers, chap!

good point, but perils isn't as simple as it used to be, and can be a huge buff 1 time out of 6 and mostly just removes one wound, so multi-wound psykers are a bit more dangerous.

that doesn't change your point that daemon-summoning seems to be more random and dangerous than it's worth. and you still have to roll on the table to even get the appropriate powers.

Where are these figures coming from?
Do you have to roll a 4(+) to manifest a power now?

yeah you need to roll a 4+ for each warp charge.

SO a WC 1 needs at least 1 WC, a WC 2 at least 2 etc.

But you can use any number of dice?
Perils is?
Deny is?

Need to get the new book at some point.

Boniface wrote:
But you can use any number of dice?
Perils is?
Deny is?

Need to get the new book at some point.

You get to use d6 + the number of psychic mastery levels in you army per psychic phase to attempt to manifest your available powers.
If you roll 2 or more 6s during each manifestation roll, you must roll on the perils table.
To deny the witch, you need to roll as many 6s as your opponent rolled successful manifestations.
DtW is normally 6+, 5+ if the model targeted is also a psyker and 4+ if it's a psyker of higher mastery level.

DtW can now be used on blessings, but I don't know if you can modify your 6+ in that case. Can anyone answer that one?

Boniface wrote:
But you can use any number of dice?

You get a pool of D6 + your army's total Mastery Levels. You can spend as many as you like on each power.

Boniface wrote:
Perils is?

Any result of two or more sixes for most powers. Any double for Daemonology powers (unless you are a Daemon or a Grey Knight).

Boniface wrote:
Deny is?

Similar to casting, but you need a 6+ rather than a 4+. One success needed for every success the caster got. You get a bonus to the dice roll if the power is targeting a unit which has psychic defences, such as Adamantium Will.

 pocketcanoe wrote:

DtW can now be used on blessings, but I don't know if you can modify your 6+ in that case. Can anyone answer that one?

I don't have the rulebook. But multiple people who do have stated online that to deny blessings it is always a 6+ with no modifiers. If they fire off a blessing with three 4+s, you'd need three 6s to stop it. If they succeed with two 4+s, you need two 6s. Etc;

That's what I've seen posted from multiple sources.


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 pocketcanoe wrote:

Looking for two 4s: (WC 2)

1) 0.000
2) 0.250
3) 0.500
4) 0.688
5) 0.813
6) 0.891
7) 0.938
8) 0.965
9) 0.980
10) 0.989

Awesome charts man.

Anyway, since Prescience is WC 2 now, it isn't so overpowered anymore. Before it was a no brainer. Now in 7th edition I'd need 6 dice to have almost the same but worse odds as I did in 6th edition with a LD10 psyker. It would be a bit tough to cast it three times with three pyskers in an army. Even with a warp charge spamming army like GK. And for armies that can't spam / farm psykers? Oh boy, multiple WC 2 and 3 spells are going to be very hard to pull off...

Can't we do binomial distributions in our heads? do we really need tools to do "what's half of half?"

 Scipio Africanus wrote:
Can't we do binomial distributions in our heads? do we really need tools to do "what's half of half?"

Say what? I could only do the first simple chart in my head somewhat.

You must be a math genius like that Russel Crow in that Handsome Brain movie about Steve Nash.

Super Newb wrote:

 Scipio Africanus wrote:
Can't we do binomial distributions in our heads? do we really need tools to do "what's half of half?"

Say what? I could only do the first simple chart in my head somewhat.

You must be a math genius like that Russel Crow in that Handsome Brain movie about Steve Nash.

1/2*1/2=1/4.

Please clarify Deny the Witch.

If a power is WC2, and the psyker rolls 2 successful 4+... in order to Deny, most the opposing player nullify 1 WC or both?

Just found a near identical thread over in tactica:

http://www.dakkadakka.com/dakkaforum/posts/list/596200.page

If my AM psyker summons a unit of 10 horrors or a tzeench herald , do I automaticly gain power dice for more psyker levels on the table or do I get them next turn ?

Makumba wrote:
If my AM psyker summons a unit of 10 horrors or a tzeench herald , do I automaticly gain power dice for more psyker levels on the table or do I get them next turn ?

Since warp charge dice are generated at the start of the phase, I'll wager you have to wait.

You seem really good at math, and I am terrible at figuring out percentages. Would you mind terribly giving me the odds on rolling a specific power with a Level 3 Psyker on a chart.

For example : What are the percentage odds that you would roll a Possession when choosing all powers from Daemonlogy with a Level 3 Herald.

If you could do this that would be so awesomely bestest.

I read the psyker rules and i noticed something a bit off that kinda makes no sense.

Mastery Levels.
I saw nothing indicating that you cannot learn a spell that takes 2 charges if you are a ML1, like before. No big deal as the warp pool changed.
However i also saw that the ML has no effect on harnessing the warp. That could just be a balance thing, but fluff wise you would think a ML3 psyker would probably harness the warp on a 3+ or something at the least. Or even allow a reroll by default just for being ML3+

Did i miss something, or are literally every psyker rolling 4+ to harness each warp regardless of ML? Some wargear might get faq'd to modify the result, since it says in parenthesis (before any modifiers) when it refers to rolling 2 or more 6s while harnessing warp.

 Vineheart01 wrote:
I read the psyker rules and i noticed something a bit off that kinda makes no sense.

Mastery Levels.
I saw nothing indicating that you cannot learn a spell that takes 2 charges if you are a ML1, like before. No big deal as the warp pool changed.
However i also saw that the ML has no effect on harnessing the warp. That could just be a balance thing, but fluff wise you would think a ML3 psyker would probably harness the warp on a 3+ or something at the least. Or even allow a reroll by default just for being ML3+

Did i miss something, or are literally every psyker rolling 4+ to harness each warp regardless of ML? Some wargear might get faq'd to modify the result, since it says in parenthesis (before any modifiers) when it refers to rolling 2 or more 6s while harnessing warp.

It's like that. no way to become 3+.

Hollismason wrote:
You seem really good at math, and I am terrible at figuring out percentages. Would you mind terribly giving me the odds on rolling a specific power with a Level 3 Psyker on a chart.

For example : What are the percentage odds that you would roll a Possession when choosing all powers from Daemonlogy with a Level 3 Herald.

If you could do this that would be so awesomely bestest.

I think it's 1-((5/6)*(4/6)*(3/6)), or about 72%. Two rolls is about 44%. Four rolls is about 91%.

 Vineheart01 wrote:
I read the psyker rules and i noticed something a bit off that kinda makes no sense.

Mastery Levels.
I saw nothing indicating that you cannot learn a spell that takes 2 charges if you are a ML1, like before. No big deal as the warp pool changed.
However i also saw that the ML has no effect on harnessing the warp. That could just be a balance thing, but fluff wise you would think a ML3 psyker would probably harness the warp on a 3+ or something at the least. Or even allow a reroll by default just for being ML3+

Did i miss something, or are literally every psyker rolling 4+ to harness each warp regardless of ML? Some wargear might get faq'd to modify the result, since it says in parenthesis (before any modifiers) when it refers to rolling 2 or more 6s while harnessing warp.

Yep, mastery level only influences the number of different powers you can generate and that psyker's contribution to your warp charge pool. But in 6th, the mastery level only affected the number of powers you could manifest per turn and not how easy it was to manifest. So the mastery level remains irrelevant with regard to ease of manifestation.


Automatically Appended Next Post:

Hollismason wrote:
You seem really good at math, and I am terrible at figuring out percentages. Would you mind terribly giving me the odds on rolling a specific power with a Level 3 Psyker on a chart.

For example : What are the percentage odds that you would roll a Possession when choosing all powers from Daemonlogy with a Level 3 Herald.

If you could do this that would be so awesomely bestest.

Tricky, as you get to re-roll if you get the same power twice. Also, if you get the power you want on the first roll, the subsequent rolls are irrelevant. I'll try to find it if I get the chance, as it's worth knowing.

The Eldar comment - doesn't ghosthelming a power cancel the power?

Either way, while Eldar are well suited to the new phase, its still a nerf, especially if they have more than 3 ML total.