Note: This page is for the first two games. Diablo III has its own page.A Hack And Slash game series from Blizzard Entertainment. Notorious for having an elaborate backstory and plot that nobody ever follows concerning a war between Heaven And Hell. As a sort of simple graphical roguelike, the pursuit of theperfect randomly-generated equipment and character build to satisfy one's inner Munchkin gives the game tremendous replayability.The first game was essentially a huge dungeon crawl, consisting of 16 levels of increasing difficulty under Tristram, the only town in the game, where various NPCs provide you with quests, healing, and equipment. The goal was to get to the Big Bad, Diablo, in The Very Definitely Final Dungeon. The non-canonical third-party expansion pack Hellfire added eight new separate levels, four new quests (a quest to kill another Diablo-esque baddy in the crypt near the church, a quest from Lester the farmer, a cow quest and a quest to retrieve a teddy bear) as well as three more characters (Monk, Bard and Barbarian) in addition to the original three (Warrior, Rogue and Sorcerer), but you had to enter a special edit to a text file to get the last two of those quests and new characters.The second game followed the storyline, which ended with the protagonist of the original game implanting Diablo's soulstone into his own forehead (it's implied that it was the warrior). Despite remaining at 640x480, it brought numerous gameplay improvements and was now broken into four acts, each with its own town and six quests per act (except Act 4, which had only three). The expansion pack, Lord of Destruction, added 800x600 resolution, two new characters (Assassin and Druid) in addition to the original five (Barbarian, Necromancer, Amazon, Sorceress and Paladin) and added Act 5, in which, after defeating Mephisto and Diablo in the original game, the player confronted Baal, the last of the three Prime Evils.The third game in the series, Diablo III, was announced in June 2008 and was released on May 15th, 2012. Trailers for it are on Blizzard's homepage.Meanwhile, the developers of the first two Diablo games, Blizzard North, resigned en masse and formed "Flagship Studios", which continued to produce Hack And Slash games, specifically Hellgate London and Mythos. After Flagship folded, the same people formed "Runic Games", which produced Torchlight. All three titles can be considered Spiritual Successors to Diablo; they certainly all play similarly.See also Baldurs Gate Dark Alliance and its spiritual successor Champions Of Norrath. A character sheet is on the works.
Absurdly Spacious Sewer: The sewers under Lut Gholein. Averted somewhat since there are passageways that are tiny and cramped and will only allow one character to move forward at a time. The sewers under Kurast are larger still.
Action Girl: The Amazon, the Sorceress, the Assassin, the NPC Rogues.
Affably Evil: "I shall take your position into consideration."
All There in the Manual: Background information for much of the series is not actually in the game, though you do get plenty of tidbits from NPCs.
In Diablo II, practically any information about items in the game, such as Horadric Cube recipes, crafted item formulas and Rune Words, or even what's a magic/rare/set/unique item and their colors, are not explained in-game, and are explained here instead.
And I Must Scream: The Diablo Warrior. You know that somewhere during his voyage to the East, he realized that Diablo has more and more control over him, and that instead of seeking salvation, Diablo will make him free another Prime Evil.
Tal Rasha, deliberately having himself imprisoned with Baal's soul inside him in much the same way, intending to fight it inside him for all eternity.
Inarius the angel. Mephisto tore the wings from his back, sliced open his eyelids, and sealed him in a prison of mirrors. He's got nothing to do for the rest of eternity except gaze upon the reflection of his ruined form.
Animate Dead: Justified on the website. Evidently skeletons are actually dirt and bone dust held together by magic, rather than actual skeletons.
Revive is the Necromancer spell that turns corpses of monsters into your minions.
The Witch Doctor's Wall of Zombies spell in the third game.
Anti-Grinding: In the first game, each floor had a finite number of enemies, limiting experience and item acquisition.
It's obvious fast enough that you can still grind by starting a new game with the same character, resetting the entire dungeon bosses and all.
In Diablo II, the website gave some official-looking lore about a boss monster named Reziarfg (derived from the name of one of the developers, G.Fraiser) but no information on where it is actually found. Thus, players tried everything to find Reziarfg, but it was really just an April Fools joke.
Armor and Magic Don't Mix: In a roundabout way. A character's ability to wear a piece of armor (aside from level and any specific class restrictions on an item) more often than not depends on how many stat points are in STR. The result is that the 'pure' mage classes (wizards in the first game, necromancers and sorceresses in the second) can't wear the heaviest armor because the player has likely put most of their stat points into INT. In other words, they can't wear the armor because they're squishy, and they're squishy because they train their minds more than their bodies. Additionally, the first game gives wizards the lowest STR cap of any class, further restricting what armors they can equip.
Equip a Barbarian with an axe (or two). Cast Berserk. or Frenzy. Literal example. Ax, crazy.
Really, every hero from 1 as well. By the sequel, the first game's Rogue is Blood Raven, the Sorcerer is the Summoner, and the Warrior is the Big Bad (though they were all corrupted by demons to some degree).
Badass: Any character who dives into hell and makes it his/her own blood soaked parking lot deserves special mention. Especially single handed.
Black and Gray Morality: See Light Is Not Good. With a few exceptions, the forces of Heaven have little to no regard for humanity. At best, they see them as pawns in their war against Hell and at worst they want to completely wipe out Sanctuary because it is part demonic.
The Blacksmith: Griswold in Diablo I. Followed by several in the second game: Charsi, Fara, Hratli, Halbu and Larzuk.
Blood Bath: One monster in Diablo II, dubbed "The Countess" in reference to Elizabeth Bathory, is described as having "bathed in the rejuvenating blood of a hundred virgins" in the tome that initiates her quest. And her room in the old tower contains a basin full of (still fresh-looking) blood.
Bow and Sword in Accord: Your warrior in the first game ought to hang on to a bow in case he gets a chance to shoot anything through a portcullis. (Most enemies can't open doors.) For the Rogue, this is much more important, as if she's caught at close range she needs a sword and shield to defend herself.
Cast From Hitpoints: A unique curse that Baal and some of his succubus minions cast causes players with more mana than health (i.e. most spellcasters) to use up health instead of mana when using their abilities, essentially forcing them to cast from their hit points.
Clowncar Grave: The infinitely annoying mummy sarcophagi. The official website says that they were never designed as a resting place but instead as a way to guard the tombs and that the fake mummies are artificially created whenever an intruder is detected.
Combat Medic: The Paladin is the closest thing to a 'healing' class in the game with his combat auras.
And, ya know, Holy Bolt, which is actually a healing spell. Still, the game consciously avoided healbots.
Baal has this as an attack. He uses them to kill Marius.
Continuing Is Painful: Dying in the original Diablo results in you dropping all your items until you can get them back, provided someone else doesn't gank them in the meantime if you're playing multiplayer. In II, they're stored in a corpse that only you can loot, though getting to your stuff in either case can be a headache in itself, especially if you died to something really tough or a swarm of them.
Cool Sword: The angelic runeblade Azurewrath (which was mentioned in the first game's manual, introduced in Diablo II as a unique crystal sword, then later updated into a much more powerful phase blade) has been given an Awesome model for Diablo III.
Corrupt Church: The Zakarum in the second game, except for the PC Paladins. The Archbishop Lazarus was part of the Zakarum in the first game, although as an individual he qualifies as Evil Chancellor.
Crapsack World: Well, technically the tie-in novels make it a Crapsaccharine World, but the games themselves focus on what happens when the veil's stripped away, followed three seconds later by the flesh off your skull.
Crate Expectations: Wonderfully averted in Diablo II. There is (usually) one interactive crate in the entire game. One. Everything else is either a barrel, a jar, or some horrible hellish construction involving Nothing But Skulls.
"Smiters" and "Kicksins" rely on combining high crushing blow (takes a large chuck of a foes HP) chances with high attack speed (to get crushing blow off a lot). They tend to be poor in non-boss non-PVP situations.
"Summonmancers" are considered by far the easiest class to solo the game with. They can not function at all in PVP unless you're able to perform a successful "tele-stomp" which involves teleporting yourself and all your minions onto someone and killing them with the combined might of their blows.
In Hell difficulty, every monster has total immunity to at least one form of attack. If you're playing a character specialized in that form of attack to the exclusion of all others, your life will be... difficult. Single-element sorceresses, and warrior-type characters who deal only physical damage, are the most common victims of this.
Damage-Increasing Debuff: Amplify Damage in II reduces the target's physical resistance, as do some other skills. Of course, enemies have similar abilities as well...
Damage Over Time: Lots of abilities and effects deal their damage slowly, poison being the most common.
According to the manual his order are masters of keeping themselves level-headed and strive for perfect balance. He is on the side of good simply because evil is in danger of winning. In other words, the trope is played perfectly straight; Dark may not be good, but it sure as hell isn't evil. (Unless the angels somehow get the upper hand...)
Deconstruction: The series as a whole is one to Heroic Fantasy. No matter how hard you fight, no matter how many hellspawn you slay, the Great Evils will always be one step ahead of you, your actions will, more often than not, help them with their goals, and they will always succeed in their plans and get what they want, even in death. Always.
Devil but No God: Averted. There isn't a devil either. In Hell you have the Three Prime Evils and their four lieutenants, and in Heaven you have the Angelic Council. Sanctuary itself was created by a relationship between an angel and demon.
Downer Ending: In the first game your character is corrupted by Diablo's soulstone and becomes one of the sequel's Big Bads. The sequel ends with Tyrael destroying the Worldstone, which is apparently the only thing holding Sanctuary apart from Heaven and Hell. Diablo III subverts that ending by revealing that it was a very good thing Tyrael destroyed the Worldstone.
In Diablo II, the Barbarian class is able to dual-wield any single-handed weapons, and use any two-handed sword in one hand (and thus dual-wield two-handed swords).
In the Diablo II expansion, the Assassin class is able to dual-wield claw-class weapons, and has a passive skill to use them as a shield while doing so.
The Bard had a crude form of it; they reused the Rogue animations so she's only ever shown holding one sword, but gets double damage and the ability to hit multiple enemies simultaneously when equipped with two.
Dump Stat: Energy tends to be looked down upon. There's only one, maybe two, builds where a guide does not explicitly tell you to never, ever put a point into energy.
Dying Town: Tristram in the original Diablo and the Kurast Docks in Diablo II.
Easy Levels, Hard Bosses: Boss fights in the series are often a lot more difficult than the areas before or after them. The Butcher in I Duriel in II are two good examples.
Elite Mook: Quite literally. Elite mooks basically have a different colored name, more hit points, some new powers, and drop higher loot. Otherwise, they're the same as their type. They also tend to be surrounded by a cadre of their type, which are normal except for a single buff.
Evil Sounds Deep: No matter what game he's in, Diablo rocks the evil demonic voice.
Expanded Universe: A number of novels penned in the world of Sanctuary, including the Word Of God canonized Sin War Trilogy starring the Sanctuary equivalent of Heracles/Jesus set thousands and thousands of years before the games take place.
Experience Booster: The Experience Shrines in Diablo II provide a temporary boost to your experience gain rate.
Fallen Angel: Izual, Inarius, Imperius, and probably others. The apparent lack of any Ascended Demons bodes ill for the fate of the setting.
Fallen Hero: All three player-characters from the first game wound up this way by the time of the second. The warrior became possessed by Diablo's soulstone, becoming the Dark Wanderer and eventually Diablo himself; the rogue...well, Blood Raven's her; and the sorcerer became the Summoner who's causing Lut Gholein a small hell's worth of grief. And possibly every hero from the second game has gone Ax Crazy or some other form of loopy. Yes, the Paladin included. Or maybe not, if Diablo III is any indication.
Fake Difficulty - Loads of it once you get to the aptly-named Hell Difficulty. -100 to all of your resistances, life and mana stealing is drastically reduced, minions and mercenaries are Nerfed beyond recognition, every enemy is immune to something (except act bosses, some really special superuniques, quill rats and hell bovines), massive experience loss upon death... the list goes on.
Arguably not "fake" since excelling at the various skills that the game demands (item collection, character building, etc.) allows you to overcome these penalties and then some. Well-made characters can exist quite safely in almost all areas of Hell. Particularly optimized defensive builds can literally be parked and left unmonitored for extended periods of time in all but the most dangerous of areas.
Pre-1.10 MSLE, and to a lesser extent, post-1.10 LEFE, LECE, or LEFECE monsters probably still count, though, since dealing any damage to them can mean insta-death.*
LE, or Lightning Enchanted, causes a monster to release sparks when hurt. The other modifiers mentioned either greatly increase the number of sparks (MS or Multi-Shot), or add enormous amounts of damage to them (FE and CE, or Fire Enchanted and Cold Enchanted).
Fighter, Mage, Thief: Played completely straight in Diablo, with the Warrior, Sorcerer, and Rogue, respectively. In Diablo II, the archetypes get expanded on and diversified, with the Paladin and Barbarian descending from the Warrior, the Assassin and Amazon descending from the Rogue, and so on. Most classes can be played as two or even all three types, though.
Fireballs: It has fire magic in it after all so that's almost compulsory.
One of the Paladin's powers adds all three of these to his attacks.
Fishing For Mooks: A strategy in some cases as you do not want to go wading into large melees, the barbarians taunt can be used to lure enemies away from other enemies. This can help in defeating fallen shamans but is generally regarded as a waste of skill points.
Waste of skill point, arguably, though the ability to get basically any monster that does anything complicated or dangerous to stop doing it and instead walk right up to you and get its ass kicked is handy sometimes.
Fling A Light Into The Future: Evilly subverted. Azmodan pulls this with himself and his forces, sealing himself away until the heroes who defeated his fellow Prime Evils would be unable to stop him.
"You knew it would eventually come down to this. Kill Baal. Finish the game!"
Get On The Boat: You need access to a ship to get from Lut Gholein to Kurast in II.
Giant Space Flea from Nowhere: Technically Duriel. He is an important lore character and has a detailed backstory, but unlike Andariel he received no build up or foreshadowing for his fight.
Somewhat justified since he's essentially a Bait-and-Switch Boss there to end the act with a twist by making the player think they're about to face Baal.
The Gods Must Be Lazy: There doesn't seem to be a God in the setting (with the Prime Evils dividing up the duties of Satan) but the angels of the High Heavens are more concerned with their law of non-interference than those of the mortals of Sanctuary. Though this could just be Imperius. The demons from the Burning Hells, of course, aren't picky with their prey, so the world is just as crappy as you'd imagine as a result.
Although one angel, Tyræl, does eventually decide to take matters into his own hands (and gets his ass kicked.)
Guide Dang It: Many game mechanics are not described in game or in the manual. Attack speeds, for example, in Diablo II are different between characters, do not often correspond to the descriptions given for items, multiple attack moves like Zeal and Strafe increase the speed in unusual ways, and these and other properties are not described anywhere, they had to be found by outside players in outside guides.
There's a guide written up for the technical details how poison damage works, including how it gets overwritten and how to convert damage over time in-game as relates to time IRL, to help use it viably as a damage-over-time effect. Without knowing this, it's easy to overwrite/nerf your own damage and come to the conclusion that poison simply sucks.
This is compounded by the so-called "LCS" - or "Lying Character Screen". Literally the only number it can't get wrong is your level, and inaccurate stats can appear as early as level 3. The attack (and related chance to hit), defense (and related chance to be hit), and damage numbers are particularly meaningless, having absolutely no relation to the actual figures used once you have a few different sources of bonuses to these things.
Half-Human Hybrid: Goatmen and catmen. Also inverted, humans are in fact demon/angel hybrids.
Hard Levels, Easy Bosses: For most decently well built characters, act bosses tend to be more of a punching bag than any challenge. The real killers in the game? Multiple packs of unique and minions, bosspack archers and other dangerous melee monsters like frenzytaurs, gloams and tomb vipers, and generally speaking powered up regular mooks.
The Burning Soul is a poor example, simply because its damage is bugged. It is supposed to do 42~108 damage, but it actually does five times this figure because of a code bug, instantaneously making it the most dangerous monster in the game (pre-1.13, Iron Maiden using Oblivion Knights would have been competition; see below).
The Burning Soul is still extremely dangerous even with patch 1.13. The combination of fast, extremely long range, and high damage lightning that are rapidly spammed, which means a character without maxed lightning resistance in hell difficulty will die extremely quickly.
The Necromancer skill Iron Maiden bounces cause enemies to take 6.75x of damage they deal with their melee attacks. It's not an effective skill in Nightmare and Hell difficulties. On the other hand, Oblivion Knights using Iron Maiden was extremely deadly to players that rely on melee attacks, until patch 1.13 removed this skill from this monster.
Nihlathak's Corpse Explosion deals only 20% damage in Hell difficulty. And well-geared players still get owned by this badly.
Players deals 1/6 damage to other players.
As of patch 1.10 and later, monsters have +50% HP, +50% EXP and deals +6.25% damage for each additional player in the game beyond the first.
The game does not display flying damage numbers anywhere, just graphical health bars.
It's possible that poorly geared characters, that can deal more damage than their own HP, end up having trouble killing monsters in hell difficulty.
Ice Breaker: Using cold magic or cold-enchanted equipment can shatter an enemy to bits, leaving no corpse. This works best against skeletons in Act II.
It's also a good backup plan when you try to Cut Off The Snakes Head in a pack of enemies where lieutenants revive mooks and a unique revive lieutenants but fail because it's too tightly packed to allow you access to the unique. Destroy enough mooks that cannot be resurrected and suddenly their rapid-fire reviving is worthless.
Inexplicable Treasure Chests. Even in hell. To be fair, the chests there are skeletal cages and corpses. Although most of them are called "Hidden Stash" or similar, which is really weird since they usually stand in the wide open and consist of neatly tiled skeletons and a flickering flame.
The sequel isn't nearly as bad as the first (Act II is a desert, with each region surrounded by cliffs; Act III is a jungle, and the trees are apparently solid walls; Act IV is Hell, at first on floating rocks in a field of darkness, and then islands on a river of fire; Act V is a mountain, and portals into Hell, and a big scary dungeon full of big red crystals), but Act I is a bunch of fields, surrounded by stone and wooden fences that a child could jump over.
Light Is Not Good: The angels initially wanted to destroy humanity due to being descended partially from demons. This changed when the Council voted to spare humans on seeing their possible nobility. Imperius is the only one on the Council to continue to call for humanity's destruction and attempts to prevent any angelic attempts at aiding humanity. Given his status as commander of heaven's armies and the angels' believe in order it greatly impedes the other angels from acting.
Not... really. Casters are easier since they depend less on items (most Fighters basically require quite good items to succeed, while some casters can get by with any old thing), and the Sorceress has free access to Teleport which makes a huge difference, but for the toughest bosses, a Fighter is always better. A "Smiter" can beat Uber Tristram with relatively mediocre items; for a Sorceress, it's almost impossible without preposterously rare items.
Averted in PvP: every single class has several builds to duel with at each PvP level cap. There are melee builds dubbed "caster killers" for how effectively they can trash Necromancers, casting Druids and Sorceresses. This is in part due to a piece of armor which gives any class the ability to teleport, a skill normally reserved for the Sorceress. Even low-level duels are well-matched between caster and melee.
But only with Enigma*
A basically-impossible-to-legitimately-obtain armor that can give anyone the Sorceress's Teleport skill.
Living Legend: The hero of the first, not so much. But of the second? Travels the world, solving everyone's problems and actually kills all three lords of hell. Living Legend.
Made of Explodium: The first game had the occasional explosive barrel and fireball, but the second is particularly bad about this. Magic can make nearly anything explode - arrows, snowballs, the earth itself, and most notably, corpses in a variety of gruesome ways.
Any monsters with the Fire Enchanted property explode spontaneously when they die, no matter how it happens, leaving only copious quantities of blood and goo. You don't want to be too close when that happens.
Magic Is a Monster Magnet: Attracting demons is an Informed Flaw of using magic, but since you have a fair chance of being torn apart by them any time you set foot outside your house anyway, at least you'll be better able to defend yourself...
Mirror Boss: Nihlathak and The Ancients use skills accessible to Necromancers and Barbarians. Nihlathak in particular is fitting, as using your abilities quick enough prevents him from using the same (very deadly) abilities against you (both use up corpses)
Money for Nothing: Money has three uses in Diablo II. Reviving your mercenary, repairing your gear, and gambling (in which you spend money on an item with unknown properties). It's still one of the best ways to get good equipment in single player.
Early on, it's a good idea to buy gear regularly. And every now and then, you can get some useful but expensive gear from the right merchant. Especially for the Paladin, the Sorceress and the Necromancer, because they need specific weapons that don't drop more often than others, and cannot be acquired through gambling.
Mook Maker: Several enemies can revive dead enemies (such as the fallen shaman). Also, the player character, if he plays as the necromancer, as he has the ability to summon Helpful Mooks (such as skeletons and Golems).
Nintendo Hard: Hell difficulty since patch 1.10 in Diablo II, where it was massively beefed up as a result of being It's Easy, so It Sucks in the prior patches. To stand a chance in this difficulty level you need to have a proper character build, to play through the game so many times over to level your stats, and the proper equipment dropable only on this difficulty at extremely low rates, to stand a chance against the later bosses.
In Hardcore mode, the difficulty of the game essentially forces you to play cooperatively; beating the game on your own requires a very specialized build and a great deal of skill and/or patience.
No Hero Discount: Demons about to overrun the countryside? Tragic. Want your armor repaired? Cash up front!
Even Tyrael and the two merchants in Act IV of Diablo II will charge money, though they at least have an excuse. Tyrael charges because he's an angel, and because of the pact, cannot directly intervene on behalf of humanity. There are similar rules for the two human merchants in the Pandemonium fortress with Tyrael.
Hilariously lampshaded in the official Diablo II online database; "In Act IV, Tyrael will resurrect your Hireling but he will charge you. What does he do with that gold? Angels got to pay the bills too."
Oddly subverted in that there are two quests, in act II and V, which will reduce prices.
Nothing But Skulls: Skullpiles as treasure chests, in addition to lying strewn about in Chaos Sanctuary. Made worse by the nature of the Random Drops game - How can you not find a skull in a pile of skulls?
Justified in that the skulls you want are the skulls of arcane demons - apparently the rest are a more mundane variety.
One-Hit Kill: Some builds are focused around doing so much damage in a single strike that they can kill any monster or opponent in PvP. Notably, the twinked Blizzard Sorceress and the Charging Paladin. It is also technically possible, with perfectly set-up gear and skills, to kill the final boss on the hardest difficulty over the course of several minutes with a single stab from a Necromancer's Poison Dagger skill.
Due to a bug in how damage is dealt when Fire-Enchanted monsters explode upon death, they can easily OHK an unprepared player. The mini-boss Nihlathak is infamous for both his potential to drop desirable items and his potential to kill even prepared players in an instant by using the corpses of his dead minions as area-of-effect bombs.
One-Man Army: Every playable character in the Diablo games can, and will, kill hundreds (if not thousands) of demons and other creatures over the course of the adventure.
One Size Fits All: A frail and shaky Witch Doctor can wear the same armor as a massive Barbarian, provided the stat requirements are met.
One Stat to Rule Them All: In most cases, non-Vitality point assignment is only recommended for meeting equipment requirements. What happened to avoiding getting hit, and so being able to add to strength and agility? Well, all right, so far it's only Amazons who get to enjoy Slow Missiles...
One Time Dungeon: The Cow Level is intended as such — you can't open the portal anymore if you kill the Cow King, or if you're there when someone else does. But you can still enter the level through someone else's portal.
Our Angels Are Different: Light tentacles instead of wings, tend to wear armor and face-concealing cloaks. As far as alignment goes, they are ostensibly on your side, but don't expect any help from anyone other than Tyrael. Strict followers of a law of non-interference again with the exception of Tyrael and a few other angels.
Overdrawn at the Blood Bank: And not just monsters. The Paladin in Diablo II has a skill called Sacrifice, which grants him bonus damage in exchange for losing some health. Every time he uses the skill, about a gallon of blood spills out of him.
Overshadowed by Awesome: It's hard to make the Diablo II expansion climactic when the previous game ended with you effectively beating the Devil in Hell.
Palette Swap: The different monster varieties, from 3 to 6 variants, as well as champion/unique monsters.
Pamphlet Shelf: Bookshelves in the series usually yield a single spell tome at best.
Perpetual Beta: Both games have suffered from this. Diablo had a long history of Good Bad Bugs and Game Breaking Bugs, most notably item-duplicating, in its day. The second game is more notable for being in this state even after a decade of semi-annual support. Most skills are bugged and many are outright broken even after ten years of patches. A few particularly offensive examples of bugs that still plague it:
The "Lying Character Screen". Due to the character screen not being updated in patch while fundamental game mechanics have been, the character screen is notorious for displaying incorrect numbers for every gameplay value except the player's name, level, experience, and health.
Melee spear skills for the Amazon class are so broken that players will call you crazy for considering them. One skill has such a slow animation that a monster can walk away before it lands. There's also a multi-strike skill that, as soon as any hit misses in the sequence or is interrupted (including by any of the Amazon's passive damage avoidance skills), all subsequent hits will miss while the animation plays out and you are beaten to death.
Both skills that use a certain attack animation, which looks like a continuous blast of flame or ice, can only hit one target. Furthermore, these skills do less than 1/3rd the damage they should. This is because the missile used disappears once it hits a target, rather than continuing to exist to deal damage in spite of the ongoing animation giving the illusion it's working.
There is the Gloam enemy that has two attacks: a powerful touch-based attack and a ranged lightning blast. The damage from the first attack is inexplicably added to the damage from the second attack making it one of the most infamous monsters in the game.
Due to faulty coding a Viper enemy, on Hell difficulty, fires poison blasts from its mouth that leave behind invisible hitboxes that do massive physical as well as poison damage and hit up to 12.5 times per second. This can and will kill any character not specifically built to fully negate the damage to be killed within seconds if they meet the conditions to trigger the bug. The conditions? Walking, or having an ally stand near you. They're also notorious for murdering your NPC ally without a moment's notice. Veteran players will usually just Save & Quit rather than deal with them.
If a boss monster gets a certain kind of randomly generated Mana Drain power, it drains 512x as much mana as intended. This makes it go from an annoying perk to an instantly debilitating one that can result in (nearly) instant death for sorceresses who used the Energy Shield skill (which allows the player to lose mana instead of health when attacked).
Physical Heaven: Diablo II has you sent to Hell to kill Diablo. Turns out the forces of heaven have set up a fortress there and in fact have a few angels patrolling the place trying to keep things under control. Care to guess how that turned out?
Physical Hell: Of course, there wouldn't be a game otherwise. Not there originally, Diablo makes it literally out of terror incarnate.
Random Drops: a given, taking into account the genre of the game.
Rare Random Drop: At extremely slim odds for some items. For example, the chance of anything in the game dropping a Zod (the rarest rune) ranges from zero (cannot drop) to 1:some six digit number.
Mercifully, the latest patch has made the rarest runes drop more frequently - still incredibly rare, but it is now reasonably likely for a high-level player to see a few in a Season. Before it was possible for a player to never see some runes in their entire career - unless you traded for dupes.
Ranged Emergency Weapon: The bow is hardly the warrior's most useful weapon, but it can be handy if an enemy is behind a grate or if you need to exchange fire with something that won't let you close enough to engage in melee for a meaningful length of time.
Revive Kills Zombie: The Holy Bolt spell does two things: damage undead mobs, and heal friendlies.
Roguelike: The randomly-generated dungeon maps and loot, and the Save Game Limits designed to prevent Save Scumming, essentially make it a real-time Roguelike with isometric graphics and multiplayer. Hardcore mode in Diablo II features the Roguelike tradition of the permanency of death, and the option of having your corpse lootable is similar to the bones file feature of NetHack.
Word Of God says that it was a more traditional turn-based Roguelike (albeit one with isometric graphics) during early development, until someone turned off the pause between turns to see what would happen and was pleasantly surprised...
Sealed Evil in a Duel: In Diablo II, Tal Rasha uses his own body as an extension of a soulstone to imprison Baal. He is possessed, and has to be tied up and magically bound in a tomb, his spirit fighting Baal's for eternity. Or until Marius came along and tugged on the ringpull. Ooops.
Shaped Like Itself: The randomly-generated items and monsters sometimes have matching affixes, leading to things such as "Flaming Longsword of Flame" and "Ghostly Ghost".
Shout Out: In Diablo II, it's possible to hire a mercenary named "Jarulf"; being the screen name of Pedro Faria, the author of the greatest Diablo resource Jarulf's Guide.
It's also possible to hire a mercenary called "Klaatu"
And a bunch of the Rogue mercenaries are named after staff on the old "official unofficial" diabloii.net site.
Also, one of the rare 'Dirk' class weapons is called 'The Diggler,' which is almost certainly a reference to the movie Boogie Nights.
Let's not forget the lore behind the Blessed Hammer skill. If you use it, you're channeling the energy released the day when a bunch of nuns nearly sacrificed themselves to save a holy Hammer. What's the name of that hammer? Why, the Hammer of Ghrab Thaar, of course, according to the game's manual.
In the first Diablo, there was a Staff called the 'Rod of Onan' which could never ever be a reference to the Biblical story of the sin of Onan. It summoned golems from the earth.
Shoot the Medic First: Shamans have the ability to resurrect fallen enemies of their type that you've killed, so killing them quickly is very much recommended.
Skill Point Reset: Diablo II is infamous for its unforgiving skill tree system which forced many players to start the game all over again when it turned out their skill build wasn't any good later on. Fortunately a one-time reset was added in a patch, and a certain late game item also allows this, making it slightly less jarring.
Speedrun - Diablo manages to hold two speedruns that are astounding for entirely opposite reasons: The original Diablo was crushed in 0:03:12(!) through obscene luck manipulation and glitching, while Diablo II has a much longer run of 4:22:xx beating the game 100%... on Normal, Nightmare, and Hell, all from a fresh file.
Squishy Wizard - The Necromancer and Sorceress are the 'squishy' classes. The Druid can be as well, but certain builds (especially those that focus on shapeshifting) are more durable.
Despite being squishy by his stats, a Necromancer who focuses on summons is easily among the safest of heroes, having several tons of undead flesh and bone between him and anything nasty. Highly recommended for fresh solo characters, who must go it without hand-me-downs. Sorceresses focusing on Energy Shield can accomplish exceptional feats of durability as well, but it's much harder and much less common.
Take Your Time: Present in all games, although some exceptions do exist. If you don't rescue Cain from his cage in II before moving on, the Rogues will do it for you and he'll ask for a fee when identifying items.
Teaser Equipment: The enterprising young boy Wirt randomly sells a high-level item, but you're unlikely to be able to purchase it until later. Even though that item is generated at random, it's generally of a higher level than what the normal item shops are selling, though not always relevant to your class. By the time you'll generally be able to purchase it, the gear in other shops has largely caught up.
Tiny-Headed Behemoth: Blunderbores from II. Alchemical enhancements increased the physical muscle mass of those warriors far beyond normal proportions. Apparently they didn't bother to make their head proportional to the rest of their body.
Too Awesome to Use: Jewels and runes in II are just rare enough, and can only be used once.
Unwitting Pawn: The protagonist of Diablo. Even the Archangel Tyrael falls into this category a bit. Or a lot, if you believe Izual. Arguably everyone in the series was a Unwitting Pawn to the Prime Evils. Especially in the first game. Nobody ever figures out the true agendas of the Prime Evils until it's too late.
Useless Useful Spell: Averted for the most part. While at first sight anything that has to do with freezing, stunning, knocking back, fleeing, or converting won't work on anyone important, they DO work well on those "anyone important"'s minions, and a well built character (and their merc) can take on even the scariest uniques one on one if the minions are not joining the fight.
The synergy system succeeded in averting this trope, although certain skills such as Psychic Hammer and Blade Sentry are still viewed as useless beyond the first few character levels. Classic Diablo II played this straight. Minion-based Necromancer builds had to rely on golems because of how weak skeletons were and most Sorceresses had to wait until they were level 18-24 to have a single skill worth putting more than a single prerequisite point into.
Vendor Trash: Played straight with the copious amounts of low-quality weapons and armor to pawn for gold.
She described herself as a "Hunter of Evil" whose job was to hunt down rogue mages, and Tal Rasha was a rogue mage (to put it lightly), so it could be inferred that she went after Baal... but you never see her in Lord of Destruction either.
Yin Yang Bomb: The entire human race is the result of interbreeding between angels and demons.