Ok, how the actuall hell do you fight Orks?

[A Mongoose]

Doing fine and dandy in the IN campaign. Oh, a large Ork invasion, better respond to this.

And I get absolutely stomped. They have literally dozens of ships to my... Five, six maybe.

What do?

[Antiga]

Don't fight the invasion all at once. Take the hit, let em split. Also orcs are very weak in the rear.

[Ashardalon]

kill decks
kill admiral
watch them all run

novas and meltas help as IN
killing small or helpless ships helps making the others run too

[IgnoreSandra]

I try to fight them with AdMech fleets. They're slow and cannot stealth, so I usually get all three nova cannon volleys. And by that point, they're crippled and cannot engage even AdMech ships. In more general terms, Orks excel at close range high-impact fighting. You want to play cagey with them and stay as far away as possible.

Orks also have a negative to Bravery. They're very prone to just breaking and running away if the battle starts not to go their way. Same with Drukhari, AdMech, and Tyranids. Kill the admiral. Kill their decks. Use fire and nova cannons more for the morale damage than anything else.

Also, seriously consider deploying a fleet or two that's mostly light cruisers.

[Jagore]

Ork ships are slow and don’t turn fast so use a lot of bombs and torpedos and cc.

Get their flag ship and inflict lots of fire and morale damage and they will go nuts with mutiny. Aside from that kite and blast their decks and engines. They have garbage accuracy at a distance and prefer close range combat with lots of ramming and boarding.

[Wister]

AI movements in the campaign are completely predicable. They prioritize capturing zones over actually engaging in combat, and often times if there is more then one zone left to capture they will split their fleet. Your best bet is to position yourself behind the fleet that is splitting, or on a coarse that leads you into that direction. Isolate and engage and straggler ships/the slowest vessels they have or anything that was confused in the movement to the next zone. You can pick off large chunck of enemy fleets (of any race or ships type) with this method and can constantly win, nearly un-winable battles threw this kite and fight method, or simply avoid the combat completely and cap behind the enemy. The AI has no comprehension of trying to pin your fleet down or engage in advanced maneuvers. If identified they will redirect some of their vessels in your direction, but if positioned properly you will be able to maneuver out of range and they will simply return to capping points. If they continue to engage you, you are only fighting a small portion of the enemy fleet.

[Panfilo]

Melta torpedoes are particularly good against Orks because they take double damage /morale loss from fires.

Their leadership is low so if you have a fleet with Culexus assassin it can be used to good effect.

[Karl]

Focus fire the decks and they'll rush after one of your ships, use that one to kind of bait them and keep them flying after it while your other ships focus fire them down.

Also fire is good so yes Melta torpedoes are nice. They are actually your most dangerous enemy in the Imperium campaign but as long as you do this they should not be a problem at all.

[Siladen]

Get an admech fleet full nova with stasis. Build turret, the ork is gonna rush the turret, focus all nova, delete everything.

[DarkFenix]

Make sure you have turrets in the system they're going to hit, they're not going to kill anything, but they'll eat boarding actions and take a lot of aggro from your fleet.

After that it depends what kind of defensive fleet you have:

Imperial Navy? Two options, firstly and most simply, a carrier fleet works wonder against Orks, they do not like being kited since their mobility is poor, their squadrons crap, and ranged accuracy non-existent. Start with fighter spam, destroy any fighters they have and eliminate their turrets, then destroy at your leisure.

Second option is a gun and torpedo fleet, both sorts of IN torpedoes work wonders on Orks, target your firepower on their deck and watch them run away. Don't go in for a brawl if you can help it, they're better than you at it, you're going to win through critical hits and morale destruction.

Ad Mech? Their numbers won't help, you're going to nova cannon spam them when they bunch up. A well placed stasis bomb can make them bunch up even more beautifully.

Space Marine? Here's where you really want those turrets. Let the turrets eat the first wave of boarders, then go in yourself. Your ships are a lot better at boarding than theirs, and you have the armour to survive that sort of knife fight. Target their flagships and decks of other ships to cripple their morale, ram the escorts. You want a full berserk charge, show the greenies how it's done. Just don't be alongside them if their boarding actions come off cooldown, you want to eat lightning strikes instead since those do a lot less damage.

[..]

Assuming you're fighting an invasion larger than yours you'd either have to use admech like someone else said or just kite them with lock on. Things like torpedoes, nova cannons, fighters, etc. are effective when spammed. Easiest way to win is w/ domination, but if you want to do cruiser clash you can use detection to your advantage as ai usually tries to target identified ships first. Just know that if all your ships are stealthed it'll automatically aim for your flagship or the last ship it was chasing.

[A Mongoose]

Well, thanks for the advice everyone. Managed to fight off the beefy invasion, and I've got a pretty good idea of how to deal with these pesky green-skinned space potatoes.

Used defence platforms to bait them in, then started from the bottom. Escort ships, light cruisers, decks and flagships were all priority targets, and before long much of the fleet was routing.

Melta torpedoes seem to be pretty good against Orks, since the morale penalty means a ship is far more likely to mutiny because of the fires.

Lost a BC and an escort, but a minor loss and one that can be dealt with.

[Jeslis]

This is interesting information - I've skipped the imperial campaign because I dislike having to deal with the new torpedo mechanics (3 charges, no autocast/predicitive)... so I'm playing Necron..

And necron eats orcs for breakfast. I just play Cruiser Clash mode and wade into them....

It's the Eldar kiting AI fleets that give me trouble.

[Majere]

My top tip for Ork-killing is micro warp jump. Get an Admiral in a nice fat ship that bristles with guns like a Retribution, sit them in the path of the Ork horde as it advances and shoot them up with torps, bombs, strike craft etc whilst targeting their engines. Meanwhile, have some escorts or LCs in stealth head off to other corners of the map. (Defiants are nice since they can contribute strike craft.)
When the ork ships get close enough to do some damage, jump the Admiral out to the furthest other ship and open fire again. A bit of that treatment and they soon break.

[Mr Plainview]

I've noticed some really bad and strange AI behavior with orks during campaign. If the battle is a cruiser clash I just launch a few bombers across the map at the closest red blips of the ork fleet. The AI will then stop their ork fleet and bunch up around the bombers to use their combined turrets to destroy the bombers quickly. Then the AI will burn engines to advance towards me. However they are all bunched up so they just ram into each other and the AI wrecks a nice portion of their own fleet. I then launch bombers again and the same outcome repeats itself. The AI will easily destroy at least 25% of their own fleet before the shooting even starts.

[ChaosKhan]

I found that there are 4 ways to beat Orks in the campaign pretty easily.

1. Astartes - Just board them to death.
2. Nova - A salvo of 5-6 NCs devastates any ship.
3. The good old kite. Just keep your distance and focus on the engines first. Orks are slow anyway, as if you blow up their engines, they are even slower and easier to kill.
4. Full out brawl. You heard me right. You just pick the best brawler ships IN has to offer (Avenger for example), boost right through the Orks ranks and start to shoot them in the rear. With periodically activating full ahead, you can shoot them at the back indefinitely while circling counter to the direction in which they manouver their ships, without them ever beeing able to do anything more than a lightining strike to the back.