How common is this house rule? We've never played heavy air in these part, but on sunday I'm showing up with 2 thunderhawks and a pair of Thunderbolts. I'm unsure wether I should suggest that we allow CAP to attack CAP or Intercepts though. I think it's a fine rule, but I'm probably biased right now. Would you recommend that we use it?

What's the umbrella effect? From how I read the rules it would be trivial for Eldar Nightwings to avoid the AA of thunderhawks entirely, and Orc Fightabommaz would only have to accept one AA5+ shot to attack them?

As AoC says, strict RAW prohibits CAPing CAP. However quite a number of people allow this as a house rule. The main problem is that the process to resolve the situation can rapidly become quite tortuous. The situation is made more complex where one or both sides are flying their a/c within range of friendly ground AA (or AA 'umbrella') which can help protect their own side. Each formation is resolved in turn, starting with the last air formation to arrive and working through to the first one.

So for example, assume 'Red' has two formations on CAP, while 'Blue' is attacking with a bomber and one formation on CAP (acting as an escort), and the dogfight is occuring in range of ground AA from both sides. The full process is as follows:-

1. Blue Bomber declares ground assault and moves
2. Red CAP #1 moves into position by the bomber
3. Blue CAP responds and homes in on Red CAP #1
4. Red CAP #2 moves against Blue CAP

The dogfight is now resolved, starting with the last formation into the fight:-

1. Resolve Red CAP #2 situation
   • Blue ground AA and Blue CAP shoot (if in range and arc of course), Red CAP #2 casulaties removed
2. Resolve Blue CAP situation
   • Red ground AA and Red CAP #2 remnants shoot, Blue CAP casualties removed
3. Resolve Red CAP #1 situation
   • Blue ground fire and Blue Bomber shoot, Red CAP #1 casulaties removed
4. Resolve Blue Bomber situation
   • Red ground fire and Red CAP #1 remnants shoot, Blue Bomber casualties removed
5. Resolve ground attack
   • If it is still there, Blue Bomber carries out its attack

Note, AA is resolved on a unit-by-unit basis rather than by formation.
- Ground AA can fire once at each enemy a/c that pass within range of their guns (either on approach or disengagement)
- Aircraft that are flying (from previous activations) may shoot at any enemy a/c that end it's move in range and arc.
- The 'umbrella' effect is the combination of ground and airborne AA that can be used to protect friendly A/c within range.

I'm slightly confused as to what other way there is to read it if I'm understanding correctly; if you don't allow aircraft like Bombers to use their AA attacks then what would be the point of them having them?

Personally I can't say I've used the CAP a CAP rule, but I'd be fine with doing so.

Bombers have AA that can be used in self-defense when they are attacked by enemy CAP or INTERCEPT. There was an extensive debate over whether a/c (including Bombers and transport) could use their AA against other enemy a/c that arrived in their arc of fire later on in the turn, which some disagreed with (including me).

However it does provide a way to represent 'escorting' fighters without resorting to CAPing CAP. If you ground assault with the fighters first, you can then bring on the Bombers and put them in the fighter's arc of fire. The result is that the enemy CAP placed in the 'escorts' arc of fire can then be attacked before they get through to the bombers.

Isn't this a lot less effective than intercepting the fighters directly? I thought about how I'd cover a thunderhawk with 2 thunderbolts, and the best I could come up with was to have the thunderhawk within 10 cms of the enemy table edge (to force the enemy fighters to come withing 15 cms of the wing heavy bolters) and the thunderbolts covering the rear. Otherwise they can only cover 270 degrees, as all 30cm AA is FxF on these planes?

Seems like a lot of trouble to go through to get a single AA5+ shot. Should be much more effective to just let the fighters through to the thunderhawk, pray it survives and then go in and intercept the enemy fighters with an actual chance to damage them.

Isn't this a lot less effective than intercepting the fighters directly? I thought about how I'd cover a thunderhawk with 2 thunderbolts, and the best I could come up with was to have the thunderhawk within 10 cms of the enemy table edge (to force the enemy fighters to come withing 15 cms of the wing heavy bolters) and the thunderbolts covering the rear. Otherwise they can only cover 270 degrees, as all 30cm AA is FxF on these planes?

Seems like a lot of trouble to go through to get a single AA5+ shot. Should be much more effective to just let the fighters through to the thunderhawk, pray it survives and then go in and intercept the enemy fighters with an actual chance to damage them.[/quote]
A lot of that depends on the enemy planes. I've lost track of the number of 6+ (or no) save fighters that have ravaged a formation, that lived because they got to jink.

That's the main difference for the bad save fighters. Capping a CAP means a jink OR an effective action. Intercepting, allows both.

Morgan Vening
- Still f'n hates three fighter formations.

As MV says, Bomber cannot jink, so they rely on other means of defence:- their own defensive AA can usually be avoided, so this really boils down to some form of 'escort' or ground based AA.

Regarding the positioning of fighters, most have some 30cm AA weapons (some are 45cm), and you may position your fighters 5cm apart facing in slightly different directions. Doing this will provide an area that can pprotect the Bombers from close assault (within 15cm). This then presents the opponent with the choice of closing to 'point-blank' to use all weapons and risking the defensive fire of various a/c; or hanging back to use the limited number of long-range AA weapons with a reduced chance of hitting the bombers.

In this way, the 'escort' can assist merely by forcing the CAP fighters away from the Bombers thereby reducing the AA.

Aah, I can see that.

Unfortunatly I'm facing Nightwings, which can fire at full effect from 30cm. It seems like such a big swing against nightwings - if I can CAP them I stand a good chance of taking one out, severely reducing their effectivness vs thunderhawks. If I'm limited to Intercept (or pre-positioning the fighters) they have a high chance of getting to attack with all three, which gives them decent odds of killing the t-hawk outright (along with the high-value cargo).

Nightwings are considered the best fighters in the game and are rightly feared by Marines for exacly this reason. Here the defensive options are limited, but you do have several:-

1. Planetfalling cannot be intercepted, and once on the ground, the THawk and LC do provide some ground AA cover.
2. Standing down the THawks (empty) may force your opponent to use his nightwings. If you have kept your TBolts back, you can then intercept with them.
3. Try to get at least one Hunter in your army and position it so that the air assault occurs under it's AA cover (60cm). Marines usually work best attacking the flank of an army (so within ~45cm of the table edge); try using a Devastator formation advancing up the flank in support.
4. Fly the THawks on empty to perform 'flying' ground assaults; losing an empty one is much less painfull.
5. A reasonably popular tactic is to teleport terminators in on turn#1 and fly the THawk in to pick them up. This delays the 'dangerous' flying to turn #2 giving you a chance to have dealt with the NW menace by giving them a BM if nothing else (reducing the chance of their activation to 50%)
6. Use a Landing craft, which is less vulnerable to NightWings (though more painfull when lost )

But would you agree that a pair of thunderbolts on cap would limit the Nightwings, if allowed?

It seems such a game changer to allow this houserule, that even though I really like it I'm hesitant. (The guy I'm playing usually defers to me as to what rules we're using. He'll probably agree to it if I propose to use the rule, which is why I'd like to find out if it's fair or not.)

There are a number of people and groups around the world who do allow CAPing CAP (as a house rule), so it cannot be all that bad.

As a Marine player obviously you want to preserve the THawk, and the ability to place your TBolts close up to the NightWings gives you the best chance of shooting some down. As the Eldar player, you may well have deliberately played to achieve this position and want the best chance of terminating the THawk 'with extreme prejudice'! Both sides have made a number of strategic and tactical choices before getting to this position.

However, if we consider the THawk being CAPed by some less able fighters, CAPing these a/c seems a little OTT as the THawk is more than likely to survive anyway. So on balance I tend to think that CAPing CAP is not really needed - but as L4 would say DWWFY.