Evening Dakkanauts,
There have been a few threads lately commenting on how discussions in the "tactics" forum are really more about list building than how to use what you have.
I don't think this is a bad thing, really. It's always good to know what units are worth getting, even if you only play casually (after all, it's an expensive hobby). But I had the idea of starting threads focusing on how to use particular units, starting with one of my favourites - the Ork Deff Kopta.
I'm not an especially experienced player. The advice I give on here is just based on what has worked for me in the games I have played, and I openly invite the more experienced dakkanauts to chime in with their observations. I dare say a lot of it is old stuff.
Deff Koptas
For me, koptas are one of the most useful units in the Ork codex. They are cheap for what they do. They are really more of a support unit than a deathstar, but they excel in this capacity, helping your boyz make it into combat on their terms. I play using a mechanised list, but since they are not the main attacking arm, I can imagine they would be useful in a footslogging list too.
The loadout
The codex gives you three options for main weapons - twin-linked rokkit launchas, twin-linked big shootas and kustom mega blastas. Of the three, rokkits are by far the best choice. Big shootas are not terrible, but they don't really bring anything to the party as your army is already excellent at killing infantry. And really don't bother with kustom mega blastas - because they are not twin-linked, they are a lot less accurate than the rokkit and prone to killing your own guys with "gets hot" rolls, all for the sake of ap2 rather than the rokkit launcha's ap3.
So, rokkits all the way. The only problem with rokkit launchas is that you will have to either scout around for second hand copies of the old "Assault on Black Reach" version or convert your own, since the current official model comes with big shootas. However, I *heartily* recommend making the effort to do this.
Additionally, you can give your koptas buzzsaws and big bombz. I have not tried these options, and some players say they have had success with them, but to me they seem like a very expensive way of equipping your koptas to do something your other units can already do better.
You can take koptas in squads of 1-5. Personally, I take a full squad of five if the point limit allows (boyz before toyz, after all), but smaller squads are still useful - in fact, opponents often make the mistake of ignoring small units.
Tactics
So, having equipped your koptas, what can you do with them?
Anti-tank
Koptas are excellent at killing light vehicles. In bigger squads, they can take out medium vehicles and even start knocking hull points off land raiders et al. Take advantage of their speed and their scout moves to get at vulnerable side and rear armour, if you can.
Road clearance
Sometimes, opponents who don't want to be on the business end of a charging boyz mob will attempt to slow you down with a "speed bump" unit that can hold you up for a turn or two until you run out of steam, then close in for the kill by shooting you to pieces or assaulting you on their terms. Sometimes they will use weak, sacrificial units for this purpose, but more often it is something reasonably tough, such as a dreadnought or carnifex. Use your rokkit fire to clear these speed bumps and enable your boyz to get into combat when you want them to and on your terms.
Similarly, if you are playing against tyranids, use the agility of your koptas to attack your opponent's important synapse creatures in order to help prevent your boyz getting bogged down fighting rubbish but fearless gaunts.
Psychological pressure
Koptas can scout, turbo boost 24" on top of their normal move, and fly over impassable terrain. Plonking them down behind enemy lines in a threatening position will give your opponent something to think about, as he will be forced to divert fire from the main body of your force in order to deal with them or face rokkit fire at his vulnerable points.
Objective capping
The agility of koptas makes them excellent objective cappers. This is a particularly cunning use of a very small or depleted squad that doesn't look like much of a threat. My favourite example of this is when you play the mission "the relic" by scouting forward with the koptas, moving to capture the relic, and then turbo-boosting well out of harm's way!
Screening/tarpit
Boyz are the backbone of the Ork army, but you need to protect them from two things - shooting, and counter-assault (I don't mean the actual rule, I mean the tactic of the enemy charging you, a situation in which boyz are considerably weaker).
If you can see that a particularly dangerous enemy unit is closing in on your boyz, consider moving the koptas into position to get in the way. They are quite resilient, so they can absorb a lot of firepower and even hold their own in melee surprisingly well (at least until the boyz arrive to mop up).
Anti-MEQ
Orks are fairly good at killing
MEQs anyway, but koptas are particularly efficient. In theory, rokkits are anti-tank weapons, but
MEQ squads are so small that just losing a handful can be a big blow to your opponent. Your rokkits are (reasonably) accurate, wound on a 2+ and ignore their armour. And if you have weakened an
MEQ squad in this way, it might even be worth charging in afterwards to finish them off. Fun times!
Dakkanauts, you have the floor.