As for me an expansion could be smallish.

I am using my "40K Planetary Empires" tiles, 2 sets, as well as my "Warhammer Mighty Empires" tiles, 2 sets as well.

This allows me to expand my game board and turn it into any planet I like, or want it to be.

At least 192 hex tiles worth so far. Well 204 including the Hive City tiles I have.

I held off for awhile but I'm going to do it, I'm hooking some of the "Space-Port" tiles together.

Then flipping them over and filling them. So I can then secure the fortifications & the "Emperor's Palace" to them.

All I need for an expansion is the other Space Marine Chapters to get a set of "Legion Designator Discs" so they can be fielded.

A miniature of each of the Primarchs. Maybe some "Space Marine Landraiders" as well as some "Imp Walkers." And different "Titans" Please.

Things that would look cool on the board.

Cards to work with the new units & leaders. Some rules for invading Hives etc.

A Scenerio Book for the pivital invasions and battles in the book series to round out the box.

Say the first expansion covers the first 10 books. The second expansion covers the next 10 books.

Maybe even an expansion to cover the audio books?

What do you guys think?

The Corrupted One

I wonder if there ever would be a better theme ( after the siege of Terra ) for a Horus Heresy expansion or even a stand-alone game than the "Iron Cage incident" .

Look it up .

It was another golden page in the History of the Iron Warriors Legion .