Just as Good characters aren't allowed to have Bad Powers, Evil characters are not allowed to have Good powers — or, more specifically, healing powers. In short, characters on The Dark Side are generally incapable of using powers, skills, spells, or abilities that would serve to restore or protect rather than destroy.
The reason is simple: healing abilities are almost exclusively used to help others, which means that any use of such powers is almost inherently seen as selfless or kind. As such, the Big Bad can't exactly cast "Cure Critical Wounds" to heal his Mooks and still seem really Evil, despite the fact it is in his self-interest to have his mooks alive to take hits for him. Likewise, Antiheroes are likely to lack healing magic or powers. Another reason for this happening, at least in video games, is that an enemy with healing powers can get annoying very quickly. This is especially true for bosses, whose Hit Points generally far outstrip the player's; several of the most annoying bosses have healing powers.
The two exceptions to this clause are self-regeneration and necromancy — regeneration because it only applies to themselves, and necromancy due to Immortality Immorality and the general creepiness of The Undead. Many examples of the former tend to have powers that vampirically drain other people's Life Energy to heal the user.
This trope has nothing to do with actually "curing the evil". For that see Heel-Face Turn. Contrast with Good Powers, Bad People, for villains who not only get "good" powers, but use them for evil. See also Harmful Healing for one application of aversions to this trope.
Averted by Kirei Kotomine in Fate/stay night. From birth Kirei felt joy only in wicked acts. He was resurrected by an evil artifact, drained orphans under his care of life to feed his Servant for a decade, and ends up an enemy in every scenario... But his natural talents in magical surgery makes him the best healer in the story. After a lifetime of trying and failing to find enjoyment in helping others, by the time of the story he sees it as some cosmic joke.
In Gatekeepers 21, the Darker and Edgier sequel, the Ghost Girl has the Gate Power of Consumption. When Ayame rejects her, Ghost Girl's rage warps her Gate into a Black Gate; which forces her power to do the opposite. In this case, Resurrection, which pushes the Reset Button and actually does the impossible, restores everyone the Invaders have recently consumed. Whether this was intended or not is debated; even by the characters in the story.
Averted in Star Wars: Legacy; Cade's healing power which can heal almost anything insanely fast and bring back the recent dead, is a Dark Side power: it works by forcing the Living Force into a person rather than working with it.
Terminators have extensive knowledge of human anatomy. While it's actually meant to make them more efficient in killing, it could also be used to treat wounds, making this a subversion.
Averted in The Lord of the Rings, where it's revealed that Orcs do have medicine of a sort: a nasty-tasting but revitalizing liquid and some sort of healing gunk they smear on wounds.
Indeed, the Word of God states that the orcs have highly sophisticated medical knowledge that is designed to get the patients into fighting condition as quickly as possible. It's uncomfortable and leaves nasty scars, but extremely effective. They also make better weapons than any humans outside Gondor.
Averted in the companion book series for the TCG Magic: The Gathering, where Yawgmoth of Phyrexia is also one of the greatest healers in existence.
...If you don't mind being turned into a Magitech cyborg monstrosity.
Yawgmoth was not a great magical healer. He was a great surgeon. This distinction is made clear almost from his first appearance in the book to gradually deliver a big Science Is Bad message. His ability to heal was used late in the book to put living people together in bizarre ways that prevented healing magic from working so he could keep them as hostages against healers. A gouged-out eye might be regrown by magic, but not when it's still circulating blood, wiggling on the person's chest.
This trope is sometimes averted in more recent MTG novels, however; see the Tabletop entry.
Used interestingly in the books and comics of the Star Wars Expanded Universe. The Empire, in adaptations that aren't wholly simplistic, isn't simply evil. They tend to have access to the same level of technology that The Rebellion / New Republic has, including medical technology, which they use whenever it's needed. This includes prosthetics. But while the Rebel side likes to heal wounds and/or replace limbs with prosthetics covered in synthskin, the Empire is somewhat more likely to just mech everything up, not caring quite so much about how it looks. This is a bit odd, considering the prejudice against cyborgs, which is more blatant in the Empire, but that's how it goes. Naturally this is not a hard and fast rule.
In addition, some Sith possess the ability to keep grievously injured beings alive for far longer than should be possible, but don't seem to possess true healing powers. Note the Emperor in Revenge of the Sith, who was able to keep Anakin alive long enough for him to be cyborged but did nothing to repair his extensive burns. Darth Sion from Knights of the Old Republic 2 is this power taken to extremes- sheer force of will is the only thing keeping his broken body alive, and boy is it doing a good job.
Shadows of the Empire went into this slightly more. For a brief point it went into Darth Vader's POV where it was stated that he could heal himself with the power of the dark side, except the moment it began working, Darth Vader instinctively felt positive and let go of the hate needed to fuel the power.
In Allegiance, Mara Jade is the Emperor's Hand, a sort of all-purpose Force-Sensitive agent with some training. An ally of hers is horribly wounded and slowly dying, and she's helpless to do anything but try to take him to a medical capsule. The narration states that the Emperor has taught her techniques to heal herself with, but nothing she can apply to someone else.
Averted in the Wheel of Time novels. In the first few pages of the first book, The Dragon Ishamael uses a healing weave fuel by the True Source to heal Lews Therin's mind - brutally horrific healing, yet effective.
Also, the Forsaken Semirhage is the greatest Healer in the world, in either the Second Age or the Third, and a sadist as well - she causes great pain and suffering to her victims in the short time her healing takes. Joined the side of the Dark One because the Aes Sedai intended to bind her from her pleasures with an unbreakable and life-shortening bond. Further refined her abilities under the Dark One, to the point of being able to torture victims to death by careful overstimulation of pleasure centers in their brain.
Similar to the Wheel Of Time example above, The Dresden Files has Kumori, an Anti-Villain necromancer who uses her necromantic abilities to keep a man from dying until the paramedics can show up to help him. It hurts like a bitch, but it works.
The Goa'uld can heal their hosts; only the nonevil ones, the Tok'ra, are willing to risk entering a dying host just to heal them.
The Ancients can heal. They just aren't allowed to.
In Charmed, this trope is partially invoked, as, though there is no evidence that evil beings cannot heal one another, it is a known fact that Whitelighters are unable to do this (initially an unfortunate implication for the then-part-demonic Cole).
Of course, in nearly all games, the game master has the final say in how much or little healing powers the bad guy(s) the PC s are fighting have, or will use. Sure, the big bad the party has been playing hours upon hours of sessions getting to SHOULD have as many curative abilities as the PC party, but unless the GM is just a particular brand of malicious evil, they will probably only use them sparingly (a good example is when the PC party gets in a lot of good/critical rolls/hits right off the bat and the Big Bad looks to be going down WAY quicker than the GM planned for in the final epic battle, so Big Bad may bust out a healing spell that he/she will seemingly forget to use for the rest of the battle).
Evil clerics do not spontaneously cast cure X wounds spells like their Good-aligned counterparts. Instead, they can spontaneously cast inflict X wounds spells. However, even Evil clerics have more access to healing magic than most other classes; they just have to prepare all such spells beforehand, which takes away a degree of flexibility Good clerics have. (Neutral clerics can go either way.)
The blackguard, the Evil Counterpart of the paladin, does get to heal with the Lay On Hands ability, but can only use it on himself or his evil outsider mount, and his actual healing spells are limited to cure light wounds.
The healer class requires a Good alignment. Becoming Neutral, let alone Evil, results in a loss of all class abilities.
Back in the old Revised Star Wars D20 RPG, having a high Dark Side score inhibited your Light Side powers, like healing others. In the current Saga Edition, having a Dark Side score of any kind prevents you from spending Force Points to enhance your Light Side Powers. Certain Dark Side Talents (namely Embrace the Dark Side) prevent you from using Light Side powers. Maxing your Dark Side score creates a situation where there is LITERALLY No Cure for Evil; the character becomes GM-controlled (subject to Rule Zero, of course). Star Wars is also an environment where, most of the time, Redemption Equals Death, so even if the GM gives your character back, you probably won't have him back for long. Certain Sith talents, though, allow healing (in a life-force-vampire sort of way), and characters of any alignment can use a Force trance to speed their natural healing up.
And Averted by the Dark Transfer Force Power (buried in the first statblock about halfway down the page), arguably better than its Light Side counterpart.
Averted in Dark Heresy: while basic medical equipment is usable by anyone, there are a few psyker abilities that pertain to healing, and messing with the Warp is generally the road to corruption and evil.
Played straight in Warhammer, where despite the fact that the Warriors of Chaos get a magic item that lets them steal spells from enemy wizards, they are explicitly prohibited from ever using healing spells.
However, in both Warhammer and Warhammer 40K sorcerers of Nurgle have a spell that regenerates health (by overflowing with cancerous growths).
Played straight with the 'Healing' and 'Anti-Healing' magic powers in the old ElfQuest role-playing game (a combination best embodied in Winnowill); the system was percentile-based and there was a ceiling on the total of percentiles the same character could have in both, so past a certain point improving Anti-Healing would reduce skill in Healing and vice versa.
Played with in GURPS as most of the really evil-ish powers (killing with a touch, becoming a Lich) available through the magic system require the ability to heal others first.
GURPS: Powers plays it straight. The Good Power gets healing, Evil does not.
Of the five colors in Magic: The Gathering, green and white, the ones most associated with good (though the standard caveat applies), are the only sources of unconditional healing for the player. Black, the most typically evil color (ibid)), can only gain life by draining it from creatures and players first.
The kithkin from Shadowmoor are among the Light Is Not Good exceptions; they have competent healing magic, but they're bigoted assholes at best.
The Abyssal Exalteddo get Medicine charms, just like all other Exalted... but theirs generally involves stitching parts from dead bodies onto the people they're trying to heal. Have it done to you too much and you effectively become undead. Hey, it's called Necrosurgery for a reason!
Averted in The Elder Scrolls series. Necromancers and enemy wizards have access to the same spells you do and can heal anytime they have the magicka to. It can be especially annoying when they don't bother to heal themselve until they reach a certain (low) hit point count, so that the player feels they're close to winning the battle and then *brring*, the opponent regains two-thirds of their health. This also prevents killing high-level wizards entirely with sneak attacks, as it's possible to put five or six arrows into them while they're running around looking for the high-level sneak, but before they can be finished off they just heal instantly.
Averted by a few creatures in the Dragon Quest series; for example, healslimes, cureslimes, and the Elysium Bird all heal other creatures (and have poor attacks themselves), and at least one creature in Dragon Quest VIII that will cast a suicidal spell that revives or heals the rest of its party. Bosses generally heal themselves but not others.
One of the grotto bosses in Dragon Quest IX (Shogum, a gigantic slime knight) doesn't cast healing spells himself... instead, he can summon a king cureslime. What makes this really nasty is that king cureslimes can cast Omniheal, which heals all enemies for 999(a very sizable section of his 3600 HP health bar). Here you definitely want to Shoot the Medic First!
Subverted in Dungeon Keeper. Healing is an important spell, especially to prevent heroes from dying during torture.
Averted in Jedi Outcast and Jedi Academy. In the former, Kyle Katarn has a more neutral outlook at first, and has a mix of dark and light Force powers (including self-regeneration), before becoming a Jedi. His more relaxed perspective on dark vs. light becomes part of his curriculum in the latter game, and players can mix-and-match powers irrespective of their ultimate choice of which path to follow, and can easily heal, drain, or perform both, since the game lets you keep all your Force powers.
In Knights of the Old Republic, Force Heal is explicitly considered a Light Side power. While this doesn't mean that Sith are barred from using it, it does require a lot more Force Points.
The Dark Side counterpart to Heal, is Drain Life, which saps enemies' HP and gives it to you. Nowhere near as good for several reasons. For one, it only works in a fight, as after all your enemies are dead, there's nobody to drain from, obviously. It also doesn't give as much HP as Heal does, and you can't share it with allies. You have to rely on health potions injections.
Star Wars: The Old Republic inverts this. While Jedi Sages and Sith Sorcerers have different names for their healing spells, and likely different principles behind them, the application in terms of gameplay is the same.
Same thing applies in the first Fable game: Heal Life was a Good spell and Drain Life was the Evil healing spell.
Used in Warcraft I and II. The Horde didn't have healing powers, but they made up with necromancy and an invulnerability spell. In the expansion set for WC2, all orc heroes had three times more health than their alliance counterparts, since if they died you lost the mission.
World of Warcraft averts this by giving a number of enemy groups in an instance dungeon some sort of healer, whether for normal mob groups or even for bosses in a few cases. It's even more notably averted in one mid-level dungeon; in the Scarlet Monastery Cathedral, the final boss, High Inquisitor Whitemane, resurrects the penultimate boss, Scarlet Commander Mograine, to fight alongside her. (Given the people involved, it's clearly not necromancy.)
Also averted by playable Warlocks, Death Knights, and Shadow Priests, all Black Magic users (the first two of which use the souls of their slain foes as power for spells) who have at least minor healing abilities.
Warcraft III averts this, the Undead side having between Death Coil, Unholy Aura, Vampiric Aura, Cannibalize, and in the expansion Essence of Blight more potential ways of healing its troops than any other.
Although the orcs get ripped off, with the cumbersome to cast healing ward and nothing else (barring the expansion).
Aside from "Benediction if I feel like it" Absolute Virtue and other mobs with self-healing, there are many Final Fantasy XI enemies that play the role of The Medic. One of the best/worst examples is during a Campaign Battle in enemy territory: There are little imps that both cure and buff the Beastmen units, and do nothing but that until attacked. Oh, and every time they cast, the spell has a wide area of effect. Considering how many of the little assholes are there when a fight starts, they're the first to die.
Subverted in the original Final Fantasy. Most of the foes that the Light Warriors face off against indeed cannot cure themselves. So when Chaos randomly uses the best healing spell in the game, it comes as quite a shock. And it heals him fully.
Averted with a vengeance in most fights with Caius in Final Fantasy XIII-2. This asshole is one of very, very few enemies in the game to have access to a Regen effect that, to add insult to injury, cannot be dispelled (the heroes have nothing comparable) and is *the only one* to have Reraise on him at all times (justifying how he can appear as a Recurring Boss so much). Particularly infuriating incarnations of Caius have him perform the Regen effect immediately prior to unleashing a barrage of attacks whose priority levels do an excellent job of tossing the heroes around like ragdolls—and by the time the attacks stop, the Regen has restored him to full health.
Actually mildly subverted in that the saurian healers that the Drake faction gets are of chaotic alignment (despites the drakes themselves being lawful) and fairly strongly implied to be using black magic. Meanwhile, of the three factions with access to healers it's actually the 100% lawful Loyalists who have to go to the greatest lengths to actually acquire one; until it can advance one or more Mages to White Mages, a Loyalist force only gets healing from resting and villages just like everybody else, while Rebels and Drakes respectively can recruit Elvish Shamans and Saurian Augurs right away.
Undead heroes in Heroes of Might and Magic can in theory learn healing spells just like anyone else, though they are the most unlikely to get the required skills and spells offered from their respective sources. But even if they do, they don't work for their undead troops, but Raise Undead takes the role as healing spell instead, and their vampires have life-draining attacks. Demons are likewise handicapped, without the benefit of Raise Dead — but at least healing spells do work on them if the hero manages to get them.
In the fourth game, every faction has a different spell set associated with it. Life gets healing as soon as possible, and Nature has some regeneration abilities. Death's only healing spell is at the highest power level—it sacrifices one unit to heal another. Mind you, if you're playing as Death, you take Life Magic as a skill, and you conquer and build a mage tower in a Life or Life-allied city, you can learn proper healing and use it on your infernal troops.
In the sixth game, the Haven and Sanctuary are the only factions that have healing units in their roster and can use all the available healing spells. The Inferno faction is shortchanged since the light-based heal spells actually hurt them and they have no healing units — though they make up for this with the ability to summon extra units on the battlefield. The Necromancer faction in this game is a rather spectacular aversion. They get a healing unit, a special ability that can heal troops, and a special town building that can bring back lost troops.
Averted in Disgaea, not only are there fallen angel clerics who heal their comrades just fine, but Succubi have a skill called "Evil Healing" which restores the target's HP. It's not exactly clear what makes this different from "Good Healing."
Later installments instead call it "Sexy Healing" or something to that effect, which is more appropriate.
Of course, you can eventually gain use of almost any non-boss unit yourself. As well if you use the master-student function they can actually learn healing spells, excluding 3.
The class details do make an offhand comment about this here and there. In the first game, for instance, it's mentioned male Clerics wear dresses lined with barbed wire as penance for performing an act as 'good' as healing.
Discussed in Advance Wars: Dual Strike. The heroes are actually horrified that Black Hole would be so bold as to actually have units that can repair other units, simply because... they're evil.
In Baldur's Gate, two of the special abilities the player character gains if they've been nice are Cure Light Wounds and Slow Poison. Their "evil" counterparts are Larloch's Minor Drain and Horror.
Minor Drain still heals you when you cast it on yourself albeit a pitiful amount. It still abides by the selfish nature of evil.
Played with in Kingdom Hearts; the Green Requiems are enemies that are able to cure their allies. They have no attack abilities, however, so they could even be considered "friendly" Heartless.
Averted in three separate cases in Birth By Sleep. The first case, the final boss of one storyline and overall True Final Boss, can heal because he's taken control of one of the main character's bodies. The other two, the Vanitas Remnant and The Mysterious Figure, serve as the games' superbosses and have some creative ways of healing. The former has only one health bar but will automatically heal himself to full health if you use Curative magic on yourself (although Potions and Spells that attack as well as heal, such as Faith and Salvation, don't trigger the healing). The latter can either use Restore Barrier to heal some of his health if your attack lasts for too long or turn back time to before you hit him and smack you around a few times.
The Vile Phial is technically the Unversed version of the Green Requiem Heartless. But unlike its Heartless counterpart, it can also attack by ramming, causing poison status on impact.
In The Suffering, the more evil Torque is, the less healing pills work on him, and the more good he is, the more he's healed. Conversely, he can berserk more when evil.
In Dragon Age, you can't be healed by normal means when using Blood Magic (which is effectively evil Black Magic in the setting).
Averted and inverted in Dungeon Crawl. Some of both good and evil gods give methods of healing to your character. On the other hand, spells that heal you are only contained in Necromancy school, which the good gods forbid you from using it.
City of Villains bends the rule slightly with the healing-oriented powerset Pain Domination for villain archetypes as a counterpart to the hero-exclusive Empathy powerset (the most healing-oriented powerset in the game, where most powersets are more oriented on buffs and occasionally debuffs). Pain Domination is described as, well, manipulating the pain of others, which has a decidedly more villainous slant than the concept of having empathic powers.
Shin Megami Tensei has a select group of enemies who can and will liberally use whatever annoying healing spell they like. Superbosses like Alilat and Satan have no compunctions about using Diarahan (full HP restore) when they're near death. Even lesser enemies who know the right spells are not averse to using them. Demiurge, Captain Jack and others have lesser versions (often Diarama - mid-HP restore). The Pale Rider is a particularly evil example-he summons two flunkies to cast weakening spells. When near-death, these will self-destruct, damaging everybody else-but healing the Rider. The Rider will then use the opportunity to summon more of his flunkies.
Even the Big Bads have Priests or similar classes on their side in Fire Emblem. In fact, the closer you are to the final battle, the higher the probability is that the enemy has at least one Priest/Bishop with Physic (long-range healing) or Fortify (heals all units of the same affiliation within a ten-tile range, or in some cases, all units on the map). Some bosses also have self-regenerating abilities, most notably the three final bosses of Radiant Dawn, who possess the Mantle skill.
Runescape's Ancient Magicks spellbook (Which is tied to the evil god Zaros) is made up of only teleports and sinister combat spells, and entirely lacks in the other non-offensive spells included in the Standard spellbook and make up the entirety of the Lunar spellbook. The combat spells do somewhat make up for this in that they have added effects: the Blood spells heal the caster, the Ice spells freeze opponents, the Shadow spells lower opponents' accuracy and Smoke spells poison the target.
Averted slightly in Eternal Sonata. Several of the monsters in the game have healing special attacks. In addition, bosses will sometimes resurrect monsters that accompany them into battle.
Zig-Zagged in Dawn of War: The first game gave the (evil) orks a healer unit, but Chaos has nothing (the Space Marines and eldar have healers). In the following expansions, the (good) Imperial Guard never got a healing spell/unit, the Necrons just ressurect their dead troops, while Dark Eldar have only one unit who can Leech Life from enemies. The Tau aren't all that evil, but only one of their units can heal itself (by eating dead bodies). The Sisters of Battle have a fast-healing spell, but it's tied to a single squad and costs ressources.
Averted in Golden Sun: Many a player has been unpleasantly surprised to see Saturos cast Cure and Menardi casting Wish in the final boss fights. Menardi in particular gets some Fridge Logic since Wish is a Mercury spell and she's a Mars Adept (maybe she has an Upgrade Artifact... or some Mercury Djinn).
Aaaaaaaaaaaand played straight when the sequel revealed they weren't necessarily evil. In fact, the only Mars Clan enemy who can't cast any healing spells is the only one who plainly shows evil intentions (Agatio).
Alex still counts as an aversion, having been trained as a medic before his Face-Heel Turn in the backstory, and retaining his skills throughout the series.
The Dullahan is even worse, not only does he heal 200 HP every turn, he also has a life-draining attack.
Averted with Vyse and Co's imposters in Skies of Arcadia. Fina's imposter has healing magic just like she does, and isn't afraid to use it.
Averted in the Mario & Luigi series. Especially Mario & Luigi: Dream Team, where three out of five giant bosses and every normal boss from the Elite Trio onwards can heal, and for a significant amount of their health. This includes the two Big Bads.
Lampshaded in Adventurers!. Khrima's Chaos Healing doesn't work as well as the heroes' does; when this is pointed out, Khrima replies, "Did you actually think I was going to put a huge amount of my budget into healing research?"
Lampshaded in The Order of the Stick. After hearing that the army is suffering heavy casualties on the southern wall, Redcloak orders a squad of clerics to the area. When his second-in-command assumes that they were sent to heal, Redcloak replies, "Healing? No, they're going so they can zombify our dead. We're the bad guys, remember?"
Redcloak does have healing powers (though being an evil cleric in a D&D world, he can't cast the spells spontaneously), however, but by that point he's taken some of Xykon's We Have ReservesZerg Rush tactics to heart. Especially zombifying minions. Still, he is capable of casting all the same healing spells as a good cleric, and is even ordered by Xykon to resurrect a dead minion (admittedly, mostly so Xykon can threaten to kill him and use that guy as a replacement).
Much later a recently vampirized Durkon forgets that now being evil he can only convert spells to inflict wounds, not cure wounds, and accidentally zaps an ally.