Can I combine Heroscape Master Set 1 - Rise of the Valkyrie with Heroscape Master Set 2 - Swarm of the Marro?

Question

Or is this just possible with expansions?

Answer 1

Absolutely!  All the Heroscape sets use the same rules and terrain.  In fact, they are all intended to be used together.  Even Marvel Heroscape is compatible (And then Captain America can knock down a whole row of Marro with one shield throw!).

Mix and match to your hearts content.