Diablo is the end boss of Diablo and Hellfire, and must be killed to earn “dots” of rank on Battle.net. In multiplayer he isn’t worth more experience than a regular monster, and doesn’t drop special items, but he’s still fun to kill for the challenge of it. This page covers strategy techniques, ways to pick up his drop, tricks and tips, and much more.
Diablo is found in a closed square on the lower left quarter of level 16. In the box surrounding Diablo are at least 8 mages and 10 knights, though others (randomly spawned) are usually found in there as well. To access Diablo’s box you must throw both skull levers in the + shaped box in the top left corner of level 16; this can be done by entering the box (by throwing other skull levers on the level) or simply using telekinesis over the wall.
Diablo has far and away the highest stats of any monster in Diablo, though there were rollover bugs with his AC and to/hit prior to v1.07 that made his values in those stats quite low on Hell difficulty. Hellfire increased Diablo’s stats considerably, though his AI and other behaviors were unchanged. Here’s a quick listing of his main stats in Diablo.
Despite his very high hit points, Diablo isn’t that hard for a character with good equipment and of a sufficient Clvl. Lower level characters, or those without good to/hit, can have a very hard time landing hits on the Dark Lord. Magic users have an easier time, since Diablo is never immune to fire or lightning.
Diablo has by far the highest hit points, AC, and damage in the game (and they’re raised still further on Hellfire), so prepare for a long fight. As with any tough fight, it’s wise to stock up on potions in advance, and to make sure your equipment is fully-repaired. Drop extra potions on the ground if you think you’ll need them, since it’s faster to pick them up than try to click and drag them from your inventory to your belt mid-fight. The key to beating Diablo is the same as with most tough melee bosses; make sure you’ve got plenty of to/hit and a fast swing. Hitting him with your swings is more important than doing a bit more damage, so if you must choose damage vs. to/hit, take the to/hit. Being able to block his attacks (both his melee and his Apocalypse spell can be blocked) helps, as does doing sufficient damage to rock him.
Luring Him Out
More so than any other monster, Diablo should be fought solo; he’s hard enough without knights joining in, or Advocates launching fireballs. The easiest way to lure out Diablo is with a trick; use Holy Bolt. Diablo is a Demon, but he’s also vulnerable to Holy Bolt; the only Demon in the game who is. This isn’t a tactic to kill him; it’s just a trick to “wake up” Diablo without disturbing any of the knights or mages. If your aim is true (watch the map, aim right down the center of the room, and shoot in a straight line), Diablo will grunt in pain and come charging out to fight.
A more aggressive way to bring him out is to simply run up and let him see you. This isn’t especially advised through, since the knights will all pour forth as well. It’s possible to visually nibble your way in, moving just close enough for the knights (and mages) on one side to see you, then backing off around the corner to kill them. It can also be fun to cast fire spells into the room; guardian or fire wall are amusing, but Flame Wave is the best, since it will sweep through the entire square and hit everything not behind one of the corner walls. Note that Advocates are fire immune on Hell, and will not react to flame attacks.
Diablo has the same AI as a Magma Demon. He casts Apoc instead of hurling a flaming boulder, but he moves in the same fashion — dancing around at a distance and circling the target, before closing in to deal melee damage. This makes him hard to hit with ranged attacks. Diablo casts Apocalypse, the only monster in the game with this ability. Apoc is auto-targeting, and will hit any character in a direct line of sight, no matter how far away. (Though Diablo doesn’t cast Apoc unless he sees a valid target.)
Though Apocalypse is auto-targeting, it takes a fraction of a second to appear after it’s cast. This makes it possible to dodge the spell, if you change direction constantly. Walk in a zig zag while leading Diablo to the spot you wish to fight him in; walking in a straight line will let his every Apocalypse hit.
Apocalypse hits for physical damage. It’s not fire, lightning, or magic, and is therefore impossible to resist. It can be blocked though, like any other physical attack, and players with shields, or a Monk with a staff, can block it if they are standing still and/or fighting. It can’t be blocked while walking, or while casting a spell.
Positioning is important against Diablo, since he has a knock back hit. If you want to go toe to toe, put yourself against a wall or in a corner, and make sure he’s hitting you back against the wall. Your character will not be knocked back and can keep whacking away non-stop. You can use his knockback to your advantage if you’re lower on AC, hit points, or lack good blocking. In that case make sure there is not a wall behind you. This way Diablo will never hit you twice in a row, since his hits will knock you backwards. Keep swinging or shooting, and you’ll be able to get in a free hit or two every time you are pushed back, when he has to move forward to get back into melee range.
An oddity of this style of fight is that your character will be steadily pushed back out of their light radius. There’s a bug in Diablo in which a character’s or monsters’s light radius only readjusts if the character actually moves. If you stand still and get knocked back by attacks, your light radius will remain where you last moved, until you move again when it will jump back to display properly. This can be observed when using a bow with knock back against a boss, or (more painfully) when Diablo beats your character halfway across a level.
Since the game ends when you kill Diablo, it’s wise to prepare in advance. Be sure you’ve picked up everything you left in town and done your final shopping and repairs. If you want to do a full clear of 16, you’ll need to lure Diablo away and then return to clear out his box, before dealing with him.
In multiplayer, this is easily done by exploiting the fact that characters do not drop their equipment when they die on level 16. Simply cast a town portal somewhere out of sight near Diablo’s box, wake Diablo up, and lead him to the other side of the level. Let him kill you there, restart in town, and take your portal back down. If your character has teleport, ditching Diablo is even easier; just lead him around to the right side of the level and teleport over a wall. Be sure you’re far enough from the opening in the center of the level that he can’t pathfind his way around after you.
If you must ditch him (single player) and don’t have teleport, it can be a challenge. Lead him far away, ideally to the upper right corner of the level, and walk around the square with the bone level inside. Diablo will usually wander off in one direction or another, and if you make a break for it when he’s heading the other way, you can often shake him. He can follow you even if you’re considerably off the screen though, so be sure you break his line of sight by moving around walls or corners.
Another good way to lose him is to use Phasing. This won’t work if you’re in an open area, but if you take him into the center of the spiral section to the lower right of level 16, you can usually pop over the wall in one direction with a cast of Phasing, and ditch him that way.
Diablo in Hellfire has considerably increased stats, and his AI has been modified a bit as well. No longer will he walk right into a fire or lightning wall, but this intelligence can be used against him.
Like all Hellfire monsters, he’ll stay out of a fire or lightning wall if he’s not immune to it. Trick him with this technique. Put up a wall between yourself and Diablo, and then cast one behind him when he runs up to it and stops there. He’ll cast Apocalypse constantly, but if you put another wall on him when he can’t retreat or advance without moving into more fire, he’ll simply stand there, roasting. This is most useful with a ranged attacking character, and a rogue or sorcerer can trap Diablo, then fire arrows or nail him with spells while he’s standing helpless.
AoE spells are helpful too; make Diablo stand in a Firewall (or 10) and he’ll cook nicely while he battles you. Guardians work too, and though they’re much less damaging per second, you can cast quite a few of them, and they’ll hit Diablo even as he moves around.
Golems can help, but Diablo will smash a golem in an instant; the way to use the stone man is to let Diablo knock you against a wall so he won’t move, and then cast the Golem behind him.
Lightning is not often used against Diablo, but Lightning Wall works just as well as Firewall, in Hellfire. Chain Lightning can be used too, but not when Diablo is the last monster on the level. Lure him out with Holy Bolt and then position him so he’s between you and his box; the background of monsters inside will give you at least a dozen streams of Chain to pour into Diablo. You can use the top left corner + box as well, if you threw the skull levers over the wall instead of opening the room up and clearing out the inhabitants. No matter what the location though, Chain Lightning is tough to use to finish Diablo with on Hell. A Hell difficulty Steel Lord has 723 hit points on MP Diablo (that’s the actual value, not the buggy value displayed in the game). Diablo has 6667 hit points on Hell difficulty. So count how many Chains you need to kill a Steel Lord, and then multiply that by 9. Firewall time, indeed.
Diablo drops items like a regular monster. Not like a boss. This means that he doesn’t usually drop anything at all, and that when he does drop something it will most likely be a stack of gold or something non-magical. He does occasionally drop a magical or unique item, but the odds of this happening are very poor. Even when he does drop, there’s nothing special about it in Diablo. In that game, Diablo can’t drop any items higher level than any normal Blood Knight or Advocate on his level. In Hellfire his Mlvl is much higher than in Diablo, so it’s theoretically possible for him to drop something you’d otherwise only find from Wirt. No player has ever reported this actually happening, though.
Since the game ends when Diablo dies, his drop would seem to be irrelevant, but that is not the case. There is a way to pick up his drop, but some preparation is necessary. The player must have enough free space in their inventory to hold the item, and must cast Telekinesis before Diablo dies. Casting TK turns the cursor into a special grabbing icon; if this is ready before Diablo spouts blood, screams, and the controls freeze, then the player can pick up whatever (if anything) Big Red drops.
The hard part is killing him without being able to left click. Spells that hit over time are the best technique; Firewall or Guardian work nicely, but they must be timed properly. Furthermore, there’s a bug in Diablo that prevents a player from drinking anything from their belt while the TK grabber is active. If your health falls too low during the battle, while you’re waiting for Diablo to die with TK cast, you’ll need to left click to use the TK, drink a potion, and then cast TK again quickly.
The usual method is to fight Diablo normally, with spells, arrows, or a melee weapon, until he’s almost dead. Since his declining hit points do not show, you’ll need to count, or estimate. If you’ve killed Diablo previously with the same equipment, simply count the number of hits it took, then count the next time, and when you’re just about to that number, stop hitting and cast a few Firewalls under him, or Guardians all around the area. Then cast TK and wait. This is obviously easier with better AC and more hit points, since Diablo will continue hitting you while you’re waiting with the TK grabber.
The whole procedure takes some practice, but it’s not too tricky once you’ve gotten the hang of it. It’s not worth the trouble for the items you’ll find, which will be few, far between, and very seldom worth picking up, but there’s a sort of moral victory in not only killing Diablo, but in also grabbing his drop, simply because the game is designed to make that impossible without using this workaround.
Multiplayer Diablo’s Drop
A far easier way to get Diablo’s drop is to play with other people. Everyone on level 16 is frozen when Diablo dies, and then automatically kicked out of the game. Any player not on level 16 is unaffected, and if they have a town portal open on 16, they can easily descend to the lowest level and pick up anything Diablo dropped. The player who killed Diablo can even rejoin the game and go down a friend’s town portal, if they are so inclined.
Note that if the player hosting the TCP/IP or Modem game is the one who lands the kill, then the game will close and kick other players out. So be sure you’re the one joining the game, instead of hosting it, if you want to kill Diablo and then rejoin the game.