I really would like to know some basic tactics for HH, especially regarding the 1st scenario (brother against brother) and the opening moves (first actions Chaos and Imperial player should do).

As a Chaos player I have problems to get a decent attack going.

Feel free to post also tactics to be used in the other scenarios, including the unit set-up at the beginning.

My usual starting move as Traitors in BaB scenario is more troops for Angron in the south, otherwise the Imperials will surround him (White Scars joining in) and very likely kill his entire posse. That is unless the bombardment/corruption opened a retreat path. I always target the area with two Titans + two tanks (between the factory and the spaceport), looking to eliminate the Titans at least throught bombardment, if I can get them and corrupt the tanks, win-win.

As Imperials, unless Angron wasn't supported, Boarding Action to VS strat map usually for one point, then another order, possibly the movement one that doesn't place an activation token if executed from the strat map.

Fulgrim comes out next, usually to the south-east Spaceport (hopefully the defense laser in the fort has been removed via corrupting the defenders/coexistance battle). That way, any units still in the Spaceport have to face a corruption check in the coexistance battle. If Angron has been supported on the first action, this gives the Traitors three of the four spaceports already, could even be 4 for 4 if corruption went perfect in the north-east one.

For scenarios 2-6 (haven't tried #6 yet, but IIRC, unit setup is the same as in #2 for all the rest), as Traitor, take the north-west Spaceport first, it's the closest one to the Inner Palace (the one where Mortarion starts in scen #1). This usually leads to the Imperials taking the north-east one, they don't want two Traitors holds right next to the Palace. Place Mortarion + Magnus with their Chaos Space Marines at the north-west spaceport, they make a formidable team, Mortarion dropping combat levels and Magnus bombarding. The southern Spaceports can easily be taken with Angron/Fulgrim, since they usually hold just Imperial Guard/Tanks (you don't want to leave the Titans or Space Marines out in the open to be bombarded as the Imperial player, so they are stuck in fortifications/factories).

Thanks.

But how do you avoid Mortarion being crushed in BaB in the spaceport? He is surrounded by a lot of forces. Even though he can drop levels he is in grave danger.

He isn't in as much danger as it seems. Yes he is surrounded (then again, key bombard or two opens the path for him), but those level drops really count up. I think if all the units around him attack, Imperials get 7+2 cards (going by memory), Mortarion gets 5+2. Further, since the attacker gets to pick where he allots his damage, you can kill the Imperial Guards in the fort next to him (with the D.Laser) to get an escape route open if you want to retreat.

The problem is more to reinforce his host. When he retreats and the space port is occupied, you cannot use port landing anymore in his area, only pods (which are less available, don't go into reserve and can only deliver Space Marines). You need the pods everywhere else as well though, and moving units there from the southwestern port takes time.

Did you happen to check if my combat card calculations were correct? I did forget about Jaghatai Khan and his 2 peeps, so that would boost up to 9+2 I think. Even with that number, Imperials have to use the Assault, meaning they get 3 active iterations (1, 3 and 5 should be them). If you want, you could just pass on your iterations, save cards to block damage. All you really need in the end is one unit alive in there. You should have at least 3 Initiative to work with (if Imperials used Assault as their first card, his token is now two steps ahead, barring Diversionary Tactics). Further, all the surrounding areas now have an activation marker, so you're safe from attacks until the first Refresh Phase, plenty of time to down people to reinforce the Spaceport.

Sounds reasonable. Maybe in the future I should think more about the actual game values.

I'd love to HH out more, but that dam(n) box won't fit into my carrying bag, so we'd have to play at my place. Usually I prefer to be the one doing the travelling for gaming (don't want to inconvenience my friend more than he already has to by putting up with playing me ). Even the other stuff wouldn't be at all hard to put into another big-box, but the board is still too big.

One tactic I use is to try and corrupt imperials in the laser fortifications. Even if you just get one it will turn into a 1 on 1 coexistance battle and either knock the laser out or severely weaken it. I do not anything into the eternity wall unless I have gotten ride of at least 1 laser preferably 2. Dropping down on 3 lasers is insane. Played last night and shoot down 2 marines and a thunderhawk that my traitor friend tried to put on the ground and he still activated the sector, for nothing.

I agree with port landing down south and then act depending on what bombardments did. Don't forget that bombardments can cause breaches as well opening up the fortress.