How does Cold Blooded interact with other abilities which modify the number of dice which are rolled for a LD check? For instance, the Crystal of Midnight requires a Wizard to pass a check on 3d6, and if I remember right there's a nasty Daemons option which changes all opposing LD checks to 3d6 keeping the worst two. Any guidance on how these play with Cold Blooded?
I think he is more asking about how it works when they clash in the rules... Don't remember exactly which FAQ GW published it in, but I am pretty sure effects like that just cancel each other out and you wind up with 2d6. The crystal of midnight might work a little differently to the others, I've never faced it though.
Strewart has it right - looking for rules, not probabilities. Thanks for the stats, though, never hurts to know more
The Slaaneshite spell Phantasmagoria says "roll an extra dice and discard the lowest". So a Cold Blooded test while that spell is up would be on 4 dice, with the highest and lowest discarded.
Usually in warhammer when dealing with spell effects and magic items when you always apply the result to the models. Ergo, though lizardmen have the cold blooded special rule for our specific army spell effects which would change that (such as roll 3D6 and discard the lowest role) will over ride our special rule for that one instance only. I've not ever seen a case where a spell effect cancels out a special rule such as this case. There is always some effect which is applied and 99% of the time it'll be the spell effect.