WHAT TO DO IF PLAYING AGAINST A
NECRON DECURION

Do:

Spoiler:

- Focus on capturing objectives. (Decurions have zero ObSec. Most games won against Decuri'Crons are done so by out scoring them this way).
- Tie up their shooters in combat. (Your goal is not necessarily to kill them, so much as prevent them from being able to shoot. Necrons are usually most effective when shooting, so if you neuter them that way there's not much they can do. Note: the majority of their shooters are garbage in CC so you don't even really have to worry about your own stuff getting wiped out. Just sic something fast, disposable, and mildly survivable on them and you should be able to effectively remove that unit from the game. Bonus if your own unit is ObSec).
- Load up on AP3. (All their best stuff is 3+. Anything that's good against Marines is usually good against them).
- Take out the Spyder ASAP. (Tomb Blades being next on the target priority list. Then Stalkers. Then Destroyers and Praetorians. Anything else isn't as big a worry).
- Avoid the Deathstar. (It'll probably be combat based and very hard to kill. Luckily it'll probably also be slow. Less so if it has Wraiths. However, if it has Pylons, rush towards it and engage immediately to prevent it from firing a second time... I'm sorry, but I don't think you'll be able to stop that one's first/alpha strike).
- Beware their choppy guys. (Some of them are deceptively lethal, ie. Flayed Ones and Scarabs. Avoid getting caught by anything CC related for as long as you can).

Do not:

Spoiler:

- Aim to table them. (They're tough as nails, it's just going to end in frustration).
- Count on them being slow. (Some of them are. Many of them are not. Don't be surprised if you suddenly have a bunch of guys in your face turn two... or some times even turn one!).
- Expect to steamroll them in combat. (As mentioned above, a lot of their choppy things are actually quite effective in assault, and even their troops are hard to put enough wounds on to reliably lower their leadership to sweep).
- Fall for Wraith bait. (They're not as scary as you think, their primary role is tarpit. They're incredibly hard to kill, especially in a Harvest, so shooting at them may result in a lot of wasted shots. Best bet is to hope to engage them with your own speedy tarpit before they have a chance to catch your best unit and hold it there for the remainder of the game).
- Worry about how to kill Warriors. (Focus on killing the better stuff, they're going to be the ones really putting the hurt on you, and obviously anything that can kill T5 3+ can kill T4 4+ as well).
- Be too concerned with anti-AV. (Necron vehicles aren't that great anymore so many competitive players don't even bother bringing them. Why bother when the real star of the show is your infantry? A couple Meltas in your list should be fine, just in case).
- Stress about Gauss. (Yes, it has the potential to wound/glance anything in the game. The thing is, that only happens on a to-wound/to-pen roll of 6. So they have to be able to hit what they're aiming at, roll a 6 to wound/pen, then hope the target fails its save. Statistically not wonderful odds at doing a lot of damage. Most Necrons players are better off taking things that can do the job more effectively. Note: obviously those measly odds can be helped if you increase their number, so be aware that Warrior spam is a somewhat valid tactic. The good thing is, for it to work well they need to bring a LOT of Warriors, meaning they won't have points left for much of the scarier stuff).