Ideas for fighting Dark Eldar

I am going up against a Dark Eldar player in my schools tournement and was wondering what type of build you guys suggest I take against him. It is 1750 point games.

What army are you playing/can you play?

General advice: Shoot the Wytches and try not to get into CC with them.

oh I forgot to mention that, I am playing Chaos

the first thing you ask him when you play is which raiders he has
1. the Archon in.... shoot the hell outta him and the retinue try not to get engaged as he will eat you alive.
2. Which raiders carry the witches... another unit to shoot the hell outta before they get into close combat

The Dark Eldars shooting ability and maneuverability is insane. So if hes got a lot of the raiders watch out for him suddenly moving 24 inches with all the vehicles and being on your flank and shooting down the line on the second turn.

Most Dark Eldar units are Fleet of Foot, so they can get in your face fairly rapidly. They also have extremely high initiative, so charging them is unwise. Despite this, they are mostly S/T 3 and have a 5+ armor on many troops.

Bring out the shooty, and you should do fine. Chaos is decent in close-combat. Plaguemarines with their T5, FNP, and negation of charge attack bonuses would likely make them cry. (Though they wont get heavy weapons)

Also: They have two vehicles that look similar. One is a troop transport. One has three Dark Lances (rocket launchers that treat any armor of 13-14 as AV 12). The best armor value on either of those is 11.

Scourges (DEldar heavy weapons unit, like Chaos Havoc or SM Devastators) have jump packs, so you can potentially have deep striking sillyweapons appear somewhere.

Their Dreadnaught/Wraithlord equivalent is the Talos. It's iffy in shooting, but decent in close combat. S/T7

vindicator tank, maybe a defiler and lots of heavy bolters in your troops squads.. or missile launchers.. take out the raiders and then waste the troops.. make them walk..

The raiders are priority. Pop them with anything that can punch through AV10 (11?). Then mow down the juicy centers as they pile out. You want to stop them before they hit your lines because his assault specialists will kill you.

Just like regular eldar you want to kill the specialists before the troop choices. His regular troopers can't do much to hurt you. Incubi are a problem. Wytches are a problem. Kill them before they charge you.

Also, DE is generally assault based but they are mostly S3. A monsterous creature will be a big problem for them. Bring a demon prince with high toughness.