Editing Warhammer 40,000/9th Edition Tactics/Eldar (section)

===Imperium===
*'''Space Marines''' - The Codex giveth, and GW taketh away. With your new Codex, many of your weapons got a bump to be able to handle Space Marines. Now, with the new Armor of Contempt rule, all those extra pips of AP your weapons received in the codex pretty much mean nothing against Marines now. With ''all'' AP being reduced by a value of 1 against nearly the entire SM Codex, even your Shuriken Crits are less effective than they used to be. Fortunately, at least your forces are generally more lethal ''and'' durable to compensate. Now that all of your Aspect Warriors at least have a baked in 5++ save, your specialists all have a chance of shrugging off most conventional weaponry that would absolutely otherwise kill them. It's no reason to become complacent though; Space Marines absolutely still have the tools to reliably drop your infantry with their standard weaponry at range or up close. Despite the recent buff to their armour, your Guardians and Scorpions can still do work with the sheer number of attacks and mortal wound output they can generate (respectively). Banshees are a good option if you're looking to engage them in melee. Victory will be obtained by striking first and striking hard; if you can dictate the engagement, you'll have much greater odds of cleaning up key Space Marine units before they can wreak terrible havoc on your forces. Unfortunately, this bites both ways. If you lose initiative or allow your opponent opportunities to shoot or charge your forces unimpeded, you ''will'' suffer dramatically for it. Lastly, keep an eye on your opponent's chapter; though Space Marines in general are one of the most flexible factions in the game, each mainline chapter has a particular specialty. Avoid playing into their strengths while you search for weaknesses to exploit.
**'''Deathwatch''' - The Space Marines designed to slaughter anything not human (heretic or no), and they certainly pack the tools to do it. Try to spam Mortal Wounds against Kill Teams utilizing a Terminator or Storm Shield to tank high AP hits before you light up whatever's left of their squad and beware the hell of their Frag Cannons.
**'''Grey Knights''' - Everybody's a psyker and everybody is able to kill you at range or in melee. They're one of two factions in the entire game that can spam Smite, though most non-elite units will only deal a single mortal wound. Save your denial roles for powers from their disciplines and engage them at range; they're significantly less dangerous and have a relative lack of dedicated gunline units. As an elite subdivision of an already elite faction, you won't find it hard to outnumber whatever force your opponent is bringing to bear. With the introduction of their Tides (combat doctrines), you'll want to pay attention and avoid engaging them in matchups that compliment their current tide. You can prevent them from changing their current Tide by denying any of their Psykers attempting to use Warp Shaping.
*'''Astra Militarum''' - A horde-friendly army with no shortage of heavy armor, Astra Militarum can spam bodies and tanks from table edge to table edge and be cost effective doing it. Their main weakness is a mediocre ballistic skill and generally non-existent weapons skill (with a few select exceptions), but they make up for it by being able to fill the air with so many shots that you'll still lose something valuable by the end of the turn. Close Combat is a bit of a shortcoming for Guard players; Striking Scorpions in particular can reliably carve through them without support with their sheer number of attacks and innate 3+ save, assuming they survive any retaliating Guardsmen will struggle to do the same. Dealing with their Leman Russ tanks can be a bit trickier now that they can't really be tied up in melee, so ideally you'll want to use Wraithguard or Fire Dragons to pop them whenever possible. If you can get rid of any potential screening units, you can Webway Strike a squad of Wraithguard and drop them on top of a vulnerable tank to deal crippling or lethal damage to it. Alternatively, if you are looking for more cost effective options, a D-Cannon Support Platform can punch through heavy armor outside LoS. Lastly, the lynch-pin unit of many Guard lists are their ''officers''. Whenever possible, try to focus down any officers to prevent them from supporting units with their signature Orders; a squad or two of Rangers can usually pick off any infantry officers within a turn or two while a Fire Prism or two can burn through any tank commanders hunkered downfield.
*'''Adeptus Mechanicus''' - The Imperium's cyberpunk tech support is a mixed bag; very flexible and abundant special weapons make their basic troops particularly adept at handling virtually any standard threat while their heavier vehicles and servitors can weather no small degree of firepower before falling. Their Skitarii units share very similar statlines to aspect warriors like your Dire Avengers or Howling Banshees; reliable accuracy both at range and in melee make them significant offensive threats, but they also crumble easily enough to most standard weapons. Caution should be taken around their basic Vanguard troops; not only do they put out a significant amount of dakka, but they can also debuff the toughness of anything they engage in melee. For you, this means any S4 attacks coming in on your living infantry will wound them on a 2+, a "privilege" normally reserved for nurgling swarms. Ad Mech notably lacks much in the way of in-house psychic support and are vulnerable to your offensive powers.
*'''Adeptus Custodes''' - The most elite standard army you could face, bar a pure Imperial Knight list, that is an absolute nightmare to face in melee. Though they are exceptionally durable, they do have a bit of a weakness to mortal wounds, which cut through their fancy 2+/4++ and force them to use a 6+++ Feel no Pain. You also won't find it challenging to outnumber and outmaneuver them. Under ideal conditions, you don't want to attempt to match their close combat game under any circumstances, though in the event you're feeling suicidal, Striking Scorpions that get the drop on them can do work thanks to mortal wound output and volume of attacks. At range, which is your strength, focus on volume of fire with a decent amount of AP. Leave the guardians to sit on objectives (or the shelf at home), Dire Avengers, Warp Spiders, Night Spinners and such can throw some decent shots out at them. 
*Do note they can also take Sisters of Silence, which will fuck with psychic abilities too. They're less of a threat in melee and come in with a similar statline to your own heavy infantry. However, they have an aura that gives a -1 to psychic tests, which stacks up to -3 in 18", while also being unable to be affected by psychic powers at all and a slight bonus to attacking psykers. Warlocks in particular will have a bad time if they're caught on their own, though your typical anti-infantry weapons that'll work against the custodes will also shred these. Aim to do such before they get close.
*'''Adeptus Sororitas''' - Bolters, Flamers and Melta. The holy trinity abounds in the Sisters of Battle armies and should be expected whenever you see them take to the field. Using long range units like Rangers, Dark Reapers and Fire Prisms will let you engage the sisters well outside their conventional ranges which they'll struggle at. Despite their reliable saves, sisters are also notably squishy underneath all that armor and faith; massed fire from Guardian blobs, Dire Avengers, Windriders or War Walkers will invariably whittle through them reasonably well enough. If you're bringing psykers, keep in mind that much like the Grey Knights, every single unit of sisters can attempt to deny the witch. Unlike the Grey Knights, they are limited to only 1d6 for their denials, but they have several oppressive ways to buff their rolls and debuff your psychic tests if they're close enough. Keep your Warlocks at bay. Also worth noting they get Armour of Contempt too, just like marines which will let them ignore a point of AP.
*'''Imperial Knights''' - Very big, very scary robots that can fuck your shit up sideways if approached carelessly. More often than not they'll be used to supplement detachments composed of the other Imperial factions (like the Adeptus Mechanicus, with whom they share a lot of synergy with), but they still occasionally are fielded as a pure-strain army. In the case of the later, you'll effortlessly be able to outnumber them and maintain much higher control over the table, giving you an advantage in objective-based game modes. Your Wraithguard, Fire Prisms, D-Cannon Support Weapons and Wraithknights can deal severe damage to them with enough support. You'll have no real trouble providing it either, as again they lack much in the way of stopping your Psykers from buffing or debuffing whatever you need so that you can reliably break through their defenses.