Part 1 of this Tactica
Part 1 of this tactica is located here: Dakka Dakka Ork Takktica
Ork Tactics: On the Tabletop
Now we've got some good ideas for useful units, how should we go about playing them on the tabletop? Here are some ideas that are general enough to be used in pretty much any game, regardless of opponent or terrain.
Please note that I didn't write the other parts of the tactica; they were mainly authored by VoodooBoyz and Tacobake.
Tip 1: Sarge, Which Ork Should I Shoot First?
Target saturation is a big thing for orks. Make sure your opponent has a lot of things to shoot at so they split their fire and lose effectiveness.
Are You Threatening Me?
To work, you need to present them with credible threats. An empty trukk, a Killa Kan with no weapons, and a Warboss with Meganobz isn't target saturation; it's 1 target with a couple of minor distractions. A trukk full of Ard Boyz, 2-3 Killa Kanz with Grotzookas, and a Warboss with Meganobz is 3 very potent threats and the opponent will have trouble dealing with all 3 at once.
One last point on target saturation: the targets need to be roughly equivalent hardness. A big mob of Sluggas on foot, a Deffrolla Battlewagon, and a small mob of Tankbustas isn't good target saturation. The Battlewagon can be taken out with 1 or 2 high-strength shots (like a Lascannon) that wouldn't do anything to the other targets. the Tankbustas can be dealt with by a combat squad of marines with a heavy bolter as only a few wounds will cause them to run away; leaving the rest of the army to pour bolter fire, Vindicator shells and everything else into the sluggas to cut them down to a size where they will lose in assault. Either make all the targets big and soft (so your enemy runs out of shots) or nasty and dead 'ard (so your enemy runs out of high-strength weapons).
Tip 2: I Kill One And Another Takes It's Place.
Related to target saturation is redundancy. If your plan revolves around a single unit, it will fail. If your only option for dealing with that Death Company is a Big Mek with Shokk Attack Gun, you can bet he won't get a hit all game. If your Big Mek with Shokk Attack Gun is threatening the open areas and scaring your opponent into putting the Death Company where your Trukk full of Meganobz can assault it, your chances are much better.
Tip 3: Out Of Ammo!
Orks can field a lot of models. Few armies have the firepower to cripple orks in the shooting phase. Between Kustom Force Fields that protect your vehicles with a 5+ save, and grot screens, Killa Kan screens, and terrain that should provide most of your infantry with the same kind of protection, most gunline armies will barely make a dent before you reach them. For example a single Heavy Bolter will kill 1 1/3 orks in the open, or just 2/3 of an ork in cover, each turn. That Devastator squad will kill between 5 and 11 orks in the 2 turns it gets to shoot at them; on the 3rd turn the other 19 will be in position to charge and the Devastators are most likely gone. So don't let the enemy shooting phase worry you overly; get used to how many orks you can lose and still be effective at the other end, and use that knowledge to drive your boyz at the enemy without worrying about the losses.
On the other hand, know what losses you can't stomach. If you are going to need that unit to hold an objective later on, don't be afraid to Go To Ground with it. A small mob of Ard Boyz with a 3+ cover save? The enemy will probably ignore them in favour of shooting the things that are still coming at them (back to 'Are You Threatening Me', see?) In a couple of turns, when you need them to sit on an objective, you'll still have them and it'll be too late for the enemy to rub them out.
Tip 4: .... But Remember, They Don't Like It Up Em.
If shooting isn't your big worry, what is? Oddly enough for an army that excels in combat, it's assault - especially multiple assaults. Let's say the enemy manages to charge your big Shoota Boyz mob with something nasty; say 8 Black Templar Assault Terminators. That unit will kill (on average) around 18 Orks on the turn they charge. That's nasty if it hits one of your units... now the really nasty bit.
If those Terminators manage to get an assault on several of your units (let's say they manage to contact a big Slugga mob as well, or worse yet two other big mobs) they'll probably win combat by say 15 wounds. Your units are still big enough to be Fearless, so you'll take No Retreat wounds... 15 of them for each Fearless squad you have in the combat. That's right, you just lost 40 to 60 orks in a single assault phase. The boyz like a fight they can win, but if the enemy is truly scary - they don't like it up em at all.
- Boss Ardnutz
Other parts of this Tactica
You can see the other parts of this tactica here: Part 2, Part3, Quick Tips