Monday, 8 May 2017
It's a more granular system than Bolt Action, so no longer is a Panzer III and a Cromwell or a PaK36 and a 2pdr functionally identical, and it includes elements I think are lacking from Bolt Action such as target acquisition and better developed off-table artillery and aircraft rules.
It started with Battlegroup: Kursk back in 2012, which gave you the core rules plus information and special rules to reflect the specific theatre of war (in that case, mid-war German vs. Soviet), but they've since moved to a multi-book model in which the core rules and theatre information such as history, orbats and vehicle/gun stats are in separate volumes. I got the core rules PDF and printed and bound it myself, owing to being a cheapskate.
The hardback rulebooks are about 25 quid each. I got mine from North Star ( http://www.northstarfigures.com/ ) because they do the cheapest postage. Next on the wish-list is Battlegroup Tobruk for that early war desert goodness.