Got my 2nd core set today so I can finally play more than a skirmish game. But my set came with 3 white dice and only 1 blue dice.

Should I bother contacting FFG about it? Will I ever need to roll 4 blue dice at once?

Darnati roll 3 Blue already. If you flank with them and pick a Blue die you would roll 4 Blues.

The Kari Wraithstalker Unit upgrade card also adds 1 Blue die to a unit which could become 4 dice with flanking when used in a Unit that already has 2 Blue dice. (Daqan currently has no Unit with 2 Blue dice though but who knows what the future will bring).

Future upgrades could also make use of 4+ Blue dice.

if you don't want to pick up a dice pack as well (got mine for 5$) it could make sense to ask for the missing die

Thanks. I think I will ask. I would like to have all the right components.

Definitely contact them. Just today I've received a replacement from FFG/Asmode for a faulty red die in my core box.

Their customer service is great.

Always ask, they'll give it to you, and you can never have too many anythings.

Ask for it. They are the ones who give you half as many dice as you actually need in every game.