Editing Warhammer 40,000/8th Edition Tactics/Eldar (section)

==Psychic Powers==
The Eldar have always been psychic power-houses in their many iterations throughout 40k's history, 8th edition sees the return of reliable psychic tests, as well as more reliable ways to stop psykers. Looking at matched play rules we can see that almost every single army can cast only 6 powers other than Smite per turn (Thousand Son's daemon princes have access to 18 also.) and moreover only from their specific discipline, while Eldar can cast 24 different powers (different variations of warlocks powers are being considered separate powers)! And almost all of them may find some big use. Additionally, all but one of our powers don't need a line of sight against their targets, feel free to hide your psykers as needed.

===Runes of Fate===
These are only available to Farseers, and Farseers are only capable of these powers and Smite, so without exception, a psyker choosing from this Discipline only knows WC5 and WC7 powers; aside from Eldrad or Warlord Traits/Relics, the caster's casting ability is simply 2 powers, and once per phase, can re-roll either or both dice when casting.  This means the most reliable way to ensure your Fate powers go off is redundancy; for example, the most common power combo you're going to want on hand is either Doom/Fortune/Will of Asuryan (for D-Scythe Wraithguard) or Doom/Guide/Fortune (for almost everything else, especially Fire Dragons) - sort your powers by how much you want them to go off.  Take a Farseer with the first two powers, and a Farseer with the second two - for this example, we'll use the latter.  The first Farseer should cast Doom; if they need to use the re-roll for it, they should do so, and then cast Smite, and the second Farseer will ensure Guide goes off without a hitch.  If they don't use their re-roll, they can cast Guide themselves with the re-roll available, and the second Farseer can ensure Fortune happens, then cast Smite (with a possible re-roll available for reliability or going for 11+).  Done this way, the odds of the two powers you really care about going off will always happen with 84.95% probability each, meaning the odds of both happening are 72.17%; if you trust one Farseer to do both, your odds of pulling off both are only 65.08%.  This math was done with WC7 powers, of course - you don't need the re-roll nearly as much for Will of Asuryan or Smite, and they'll go off with 97.22% probability if you have the power available.

#'''Guide:''' WC 7. Targets a single friendly {{W40Kkeyword|asuryani}} unit within 24". Re-roll all failed to-hit rolls for the unit's ranged weapons until the next psychic phase. Works better the less accurate and more populous the unit is, of course - you won't see much bang for your buck if you have the Farseer cast this on themselves.
#*RAW it affects ranged weapons. RAI it also affects the lances on Shining Spears and the spears on Warlock Conclaves even in melee, as the points cost for both of those weapons falls under the "ranged weapons" section at the back of the codex, in much the same way as a Deathwatch Watch Master and the relic bolter shells boosting the damage of his melee attacks. 
#'''Doom:''' WC 7. Targets a single enemy unit within 24". Re-roll all failed to-wound rolls from {{W40Kkeyword|asuryani}} unit attacks against the targeted enemy unit until the next psychic phase.  Works better the harder the target is to wound, of course.
#*Bear in mind that your opponent will typically be particularly wary of Doom, so try to keep the Farseer casting it out of denial range. If you expect your opponent to attempt to deny the witch, have a supporting warlock (conclave) cast ''Focus Will'' on your Farseer for a touch of insurance.
#'''Fortune:''' WC 7. A single friendly {{W40Kkeyword|asuryani}} unit within 24" gets a 5++ FNP. Until GW decides to clear up the [http://www.belloflostsouls.net/2017/07/40k-suffer-not-wound-take.html wording mess of ignoring wounds], the generally accepted procedure is to use Fortune whenever the unit loses a wound, i.e. against all type of damage.
#'''Executioner:''' WC 7. The nearest enemy unit within 18" suffers 1d3 mortal wounds, and if a model in the unit is slain, it suffers an additional 1d3 mortal wounds.  A real rarity among psychic powers, this actually has the potential to outperform Smite, provided you target it intentionally - Smite is strictly better against one big target, but this will outperform Smite against any unit with a single-wound model in it (either natively, or because you've already damaged it).
#'''Will of Asuryan:''' WC 5.  Friendly {{W40Kkeyword|asuryani}} units within 6" of the psyker automatically pass morale, and the psyker adds +1 to Deny the Witch rolls.
#*'''Alternate Take:''' at WC 5, this is awesome filler for Eldrad to give him something to trigger his +1 to cast with; plus as the best Smite and Executioner user we have, he's usually going to be close enough to something that can use that Fearless bubble. it's also useful filler for a Guide spam Farseer if you pull Master the Warp and/or Master of Runes.
# '''Mind War:''' WC 7. Targets a single enemy {{W40Kkeyword|Character}} model within 18" of the psyker. Both players roll 1d6 and add their model's leadership characteristic to the result. If the target rolls higher or draws, nothing happens. If you roll higher than the target, they suffer a number of mortal wounds equal to the difference in score. Remember that you can use a Command Point to re-roll your d6 (and your Autarch may get it back for you).
#*Leadership bombs are viable ways of assassinating a character now, which is awesome. Have a Hemlock cast Horrify or a Warlock casting Embolden on the Farseer and maybe bring along The Visarch or some Kabalite Warriors with Grenade Launchers and use it to snipe those Commissars, Ancients and Painboys.
#*As long as it has the {{W40Kkeyword|Character}} tag it's fair game. You know who has that tag that people forget? Pask. Pask has that tag! Make sure you check your opponent's Datasheets before casting as this Power can hit more things than you realise.
#*Not to mention that the Swarmlord, Old One Eye, the Avatar of Khaine and many other immense monstrosities are listed as {{W40Kkeyword|Character}} ! If you have problems with two Flyrants, or a pesky Bloodthirster that just won't turn down for what, just submerge them in mortal wounds thanks to this trick. A good enough disparity (if well balanced with a proper casting of Embolden on your Farseer and Horrify on enemy monstrosities- always follow the ritual Embolden First; Horrify Second; Mind War Third, as this avoids your Mind War getting denied) can bring monstruous creatures down in one turn- just sit back, enjoy your superiority in the psychic phase, and watch the enemy behemoths cry salty tears as you proceed Jean Greying their arses. 
*'''Strategic Note:''' Guide, Doom and Fortune have 24" range, so with a Farseer's 8-13" movement this is more than enough to sustain any force on an average table nowadays. All this means there's '''no clear need''' for jetbiking seers anymore. On the other hand, that's still only a basic gun's range and above average movement, so while you won't usually ''need'' the jetbike, it is still pretty damn useful, mostly since it can let you reposition and adjust to changes on the battlefield.

===Runes of Battle===
Warlocks and Spiritseers always know one pair of powers, but these count as individual powers for all casting purposes, meaning the psyker in question can choose which to cast, and doesn't block another from casting the "twinned" power. All powers have a range of 18", are active for one full round, can buff only {{W40Kkeyword|Asuryani Infantry}} and {{W40Kkeyword|Asuryani Biker}}, and debuff everything. In every Serpent there will be enough room for one or two psykers to support the unit, you just have to decide which power to take!

#'''Conceal/Reveal:''' WC 6. The enemy must subtract 1 from ranged to-hit rolls against the buffed unit. The debuffed unit loses any bonuses from cover when attacked by {{W40Kkeyword|Asuryani}} units.
#* Conceal stacks perfectly well with any other source of penalties to hit, such as Rangers in cover or anything from Alaitoc.
#* Conceal is usually better than Protect, but Reveal is almost ''always'' worse than Jinx - take Jinx first if you're a Hemlock.
#** Reveal only comes into its own to remove cover from enemy sniper scout squads and make them fall back to their baseline 4+ save for easy targeting and disposal, or as an addition to Jinx.
#'''Embolden/Horrify:''' WC 6. Buffed unit gets +2 to its Leadership, debuffed -1.
#*Although this power can have a niche if a Farseer with Mind War is Emboldened, it is still ''terrible'', and basically anything else in this discipline will serve you better. Embolden is also rendered effectively useless in Iyanden lists, given the borderline morale immunity the attribute confers.
#* Although not altogether an ideal use of its one power per turn, Hemlocks can use Horrify to help build a leadership bomb. Can make quite a nasty one at that too, in mixed Aeldari comps using Phantasm Grenades and the Visarch.
#'''Enhance/Drain:''' WC 7. Target friendly unit gets +1 to hit in close combat or target enemy unit gets -1. Because it is so similar to Empower/Enervate, look there for comparison.
#* Most melee units won't need the Enhance portion of the power, since they hit on a reliable 3+, but special mention goes to Ghost Axe Wraithblades, who'll probably be escorting a Spiritseer anyways for the re-roll support they'll desperately need.
#* With Drain you get -2 to incoming melee attacks on your Howling Banshees. Forcing TH/SS Termies to hit on a 6+ at best is one of our best "soft" counters to them, now not even Rawboat gonna save'em from such disgrace. Add Lightning Fast Reactions for undiluted [[RAGE]].
#'''Protect/Jinx:''' WC 7. Target allied unit gets +1 to all saving throws or target enemy unit gets -1 (including invulnerable saves) from {{W40Kkeyword|Asuryani}} unit attacks.
#* It is strongly recommended to buff a unit with an invuln, so that your buff won't be negated by high AP weapons. Strong contenders are Wraithblades with Shields, Shining Spears, everything inside Asurmen's bubble, Guardians with Celestial Shield, or a Character heading into close combat.
#* On the opposite, there are two potential targets for the debuff: again a unit with some nasty invuln, or a target that you want to drown in saves (with Dire Avengers, Warp Spiders, Guardians, etc.)
#'''Quicken/Restrain:''' WC 7. A friendly unit moves (and may advance) a second time (but not if it came in by deep strike this turn); an enemy unit halves its move range.
#* A very versatile power that lets you react to [[Farseer|unfarseen]] threats immediately or pull off unpredictable flanking maneuvers, it is best used on a Warlock on Jetbike who can deliver this power anywhere you want.
#* With the right positioning, Shining Spears can get a turn 1 charge with this power, especially with the PHANTASM strat.
#* If you want to field a max unit of Wraithblades and don't want to pay obscene prices for a Vampire Raider to carry them, this will let them reach their targets much faster than you and your opponent might expect!
#* Howling Banshees can also become terrifyingly fast if quickened, getting an effective threat range of 23-43". You might very well catch a careless opponent off guard!
#'''Empower/Enervate:''' WC 6. Target friendly unit gets +1 to wound or target enemy unit gets -1 to wound in melee.
#* When deciding between this and Enhance/Drain: Always buff/debuff the part that has the lower probability for bigger effect (basic probability calculus). As an example, your Banshees will typically hit on 3+ and wound on 5+, hence they will benefit more from Empower than from Enhance. On the opposite, enemies with hammers, fists and other badly hitting weapons will suffer more from Drain than from Enervate. If both chances are equal, take Empower for the lower warpcharge.
#* Enervating the target of your wraith constructs also lets you relive the glorious days when S4 couldn't hurt your Wraithlords/Wraithknights. Small thing, but still nice.
====Specialist Detachment====
#'''Twilight of Gloom:''' WC 6 {{W40Kkeyword|WRAITH HOST WRAITH PSYKER}} exclusive power. Gives a friendly {{W40Kkeyword|WRAITH HOST WRAITH}} unit within 18" the benefit of cover. Potentially useful if you are fighting a lot of low AP weaponry. This power can be particularly handy for Wraithlords/seers, Hemlock Wraithfighters, and Wraithknights, due to the difficulty for such large models to attain cover naturally.

===Runes of Fortune===
A newly announced psychic discipline which made its debut in Phoenix Rising. Replaces Smite, so is usable by virtually every psyker in your army (bar the Wraithseer, who [[Fail|doesn't have any form of smite at all]]). This may be more useful to units like your Warlocks, whose smites are virtually useless due to their reduced range and damage, though it only makes it more difficult deciding which of their 3 powers is worth their 1 cast per turn.
#'''Ghostwalk''': WC 6. A friendly unit within 6" gains +2 to their charge rolls until the next psychic phase.
#*This can make a significant difference for deep striking units like Striking Scorpions or Wraithblades, who'd only have to make a much more likely 6-7" charge instead of an 8" one.
#*Special mention goes to Biel-Tan Aspect Warrior units and Howling Banshees. Biel-Tan's Court of the Young King stratagem adds 2" to charge rolls (+3" next to the Avatar who also lets you re-roll failed charges), and Banshees add 3" to their charges whenever they advance. Either give one Howling Banshee unit a long-bomb charge, or spread the love and have multiple units charge out of deepstrike.
#'''Fateful Divergence''': WC 4. Select one {{WH40Kkeyword|Craftworld}} unit within 6". They can re-roll a single hit roll, wound roll, or save roll. Lasts until your next psychic phase.
#*A niche power that ''can'' be used in lieu of the CP reroll if you're worried about a particular unit, but arguably inferior to similar powers such as Guide/Doom and Fortune (ironically).
#*Worth considering for units like Shining Spears, whose Exarch can have a 2++ invuln save with the right combo of psychic and exarch powers.
#'''Witch Strike''': WC 4. Add 2 damage to a friendly psyker's melee weapons.
#*Potentially useful, if highly situational, on Skyrunner Warlock/Farseer units. A notable example: a {{W40Kkeyword|Windrider Host}} Farseer Skyrunner carrying the ''Howling Skysword of Galaleth'' will do a flat 5 damage per swing using this power (which can very consistently be cast thanks to its paltry WC value), instantly killing most characters who fail a single save. Outside that particular example, it's a bit too situational to use.
#*Pairs nicely with Jinx, which can help make up for your Seers' complete lack of AP in melee.
#*While a Warlock Conclave is a viable target, only one model within will actually benefit from it. 
#'''Crushing Orb''': WC6. Select one visible enemy character within 18" and roll 3d6; for each result of 5+, the target takes a mortal wound.
#*Arguably worse than just using Mind War, since you can get far more mortal wounds against an enemy character more reliably if you stack leadership debuffs against them. I guess it's cheaper and you can pair it ''with'' Mind War if you want to really maximize that Farseer's anti-character role.
#'''Focus Will''': WC 6. Select a friendly {{WH40Kkeyword|Craftworld Psyker}} within 6". Until the end of your psychic phase add 2 to any psychic tests they make.
#*The 26/11/19 FAQ gave this power a much needed rewording. Now it is actually a useful tool to ensure a key psyker successfully casts whatever power you need them to. Combine this with the ''Children of Prophecy'' Craftworld Attribute and you literally cannot fail any WC 6 or less power. Notably functions for ''all'' tests they take, so you'll get more mileage using this on a Farseer or Warlock Conclave. Alternatively, as it adds 2 on top of whatever you roll it can make your opponent's Deny the Witch tests significantly harder (or impossible if you roll a 11+).
#*Eldrad can manifest powers with ridiculous ease if buffed with this. Offensively, you can cast Executioner on a 5+ and follow up with Smites that manifest on a 2+ and 3+ respectively (which do D6 damage on an 8+). Alternatively, a supporting Eldrad can cast Smite or Will of Asuryan on a 3+ then manifest any Guide/Doom/Fortune casts on a paltry 4+.
#*If you really want to maximize your psychic rolls, use this on Eldrad and pair a Warlock Conclave with him and use the '''Seer Council''' Stratagem to give Eldrad +3 to his first cast and +4 for any follow up powers. [[Meme|Power Overwhelming!]] +4 to cast is not only a super smite on 7+ but also a power that is essentially undeniable for anyone but Black Templars and Khorne worshipers with their stratagems to deny on 4+. Also Guide, Doom and other powers going off on 3+...
#'''Impair Senses''': WC 6. Pick one enemy unit within 18". They can shoot normally at units within 18", but beyond that, they can only pick the closest.
#*Probably the best of the batch, this allows you to suppress or redirect major threats to your backline units like your Dark Reapers or Fire Prisms by forcing them to target something much closer and (hopefully) much more disposable. A Hemlock Wraithfighter makes a great carrier for this power; it can force a unit (say, an Imperial Knight, for example) to focus fire on it while it employs ''Lightning Reflexes'' to impose a -2 to hit (-3 if Alaitoc and just far enough away) modifier.
#*Rangers can serve as excellent buffers when tactically deployed around a target affected by this power. Their innate to-hit modifiers make them absurdly difficult to shoot off the board (especially with proper stratagem/psychic support) and their ability to deep-strike into enemy territory almost ensures that you can place them close enough to effectively force your opponent to shoot at them instead. The best part is that at 60 points a squad, they're cheap enough that their (very likely) sacrifice won't cut too deeply into the rest of your detachment.