Hi

On the box of The Game Master's Vault it says 2x50 normal size fantasy flight card sleeves are needed.

But I only found 37 normal sized cards.

Am I missing some cards?

What WFRP books and boxes are most important to get?

What adventures are the best?

It must be print error, there is 37 normal sized cards. I've just checked my box, and it sais the same, 2 packs of blue sleeves.

Have a look here, there is complete components list available https://www.fantasyflightgames.com/en/products/warhammer-fantasy-roleplay/

I'd say the most important are Core box (unless you are going for Guides and Vaults) and Adventurer Toolkit. Rest of the expansions depends what careers your players want to play.

Game master toolkit have some nice and useful components, but for beginner GM not really needed (unless you want fancy GM screen).

4 expansion boxes (Khorne, Tzeenth, Nurgle, Slanesh) contains additional rules - combat and severe critical wounds, magic and corruption, diseases, nobility

All adventures are good. Some may require some additional work (The Gathering Storm) but it really depends what type of adventure you are looking for. For starters Eye for an Eye (Tome of Adventure) is good option which introduce players nicely into Ubersreik enviroment

I second Core + Adventurer Toolkit, after that go with the expansion boxes as each adds more interesting options in the course of fleshing out rules and ruinous powers and gives you an adventure. Lure of Power is possibly the weakest or strongest depending on how "social" your campaign is.

The GM toolkit is nice but not as useful.

Hero's Call also introduces backgrounds for move provinces than Reikland (the default human background in Core set) and different dwarf backgrounds, halfling, ogre as well.

I can also say that the Core Box + Adventurers Toolkit is a great start. Then add some or all of the boxes with the Ruinous Powers (Lure of Power, Signs of Faith, Omens of War, Winds of Magic), depending on what your campaign focuses on.

Personally I feel that Signs of Faith and Winds of Magic are the most important boxes, as they add disease and corruption rules. But it depends on your campaign.

My two favourite adventures for Warhammer 3ed is The Enemy Within and Edge of Night. The Enemy Within is a long campaign, so if you get that prepare to GM at least 30 sessions.

If you get the Edge of Night you could start by play An Eye for an Eye as suggested above and then start The Edge of Night, which is a social/investigative adventure.

Personally I feel that Signs of Faith and Winds of Magic are the most important boxes, as they add disease and corruption rules. But it depends on your campaign.

Honest question: I have the GM's Guide which also details disease and corruption but not those supplements. Is there more info in those sets that isn't in the GM's Guide or Player's Guide that would make them worth purchasing?

I believe the rules in GM's Guide cover the same rules material as the box supplements do.

If you have the hardback, you don't have the Disease cards or the Purple Corruption tokens is about all you lack on that front I think.

Now related to both of course, there are the Nurgle monsters and actions and Tzeentch similar stuff (which I like particularly) that the boxes have.