The tabletop play is essentially standard Warhammer 40k where your units have positive/negative modifiers from wargear / injuries.
You start much smaller than normal 2k games. This crusade will start at 500-1000points.
Each week there is a new scenario for you to play one side or the other of. Over the weeks and months your games effect the storyline. Because your units are gaining modifiers / gear / injuries you dont really want to trade them out between weeks as it resets their progress.
Thank you! That sounds so fun... kind of like a Bloodbowl campaign but for 40K. If a Codex comes out halfway through your crusade, does it apply when it comes out, or do you have to wait until the end? The Orks 10th Edition Codex came out a week or two ago.