Diablo 1 bugs

[Lanthanide]

Post any interesting bugs you know of here (I'm not really expecting many, to be honest).

My favorite one is how to play NM or Hell in Single player, because normally you can only play Normal difficulty. Due to the way SP works however, when you start a brand new game you'll have to start in the church and go all the way up, so it's kind of tedious if you're level 20+ already wading back through the church.

Go to start a multiplayer game, and choose a local IPX game. You'll need a clvl 20 or 30 character to start a NM or Hell game. Start the game and then quit it. Go straight to the single player option, choose your character and start a new game and it'll be the same difficulty as the multiplayer game you just started and exited.

The most interesting thing here is that you can do this with a clvl 1 character and start playing directly in NM or Hell mode. I've only tried this with playing Hell, but it's fun to only have to kill 1-2 monsters to level up - typically you will get to clvl 9 by the end of dlvl 2. However this is only really practicable with the Sorcerer because his spells hit 95% of the time and do enough damage to kill monsters quickly, whereas the rogue and warrior have To Hit scores which are abysmal against the Hell-difficulty monsters (yes, even Hell difficulty Fallen - trying a NM game might be more successful here). If you play this way you need to be very cautious because the monsters will do enough damage to kill you in 1 or 2 hits.

[Swiffer]

I know of 2 big ones. The first is a bug with Mana Shield and Stunlock.

Basically, getting stunned in Diablo is based on the mobs damage vs your health pool, regardless of whether mana shield is up or not. To ensure new characters have a lesser chance of getting stunlocked to death on the first level or 2, the game is coded in such a way that if you have 30 or less HP, you cannot get stunlocked.

This is a bug with Mana Shield, since it checks your HP, not mana, for the purposes of stunlock, so it was not uncommon to see mages running around with minuscule hit points to ensure that even if they got totally surrounded by mobs, they could cast without issue. This was exploited by letting Black Death zombies hit the mage until their HP was reduced far enough (Black Deaths permanently reduce your HP by 1 each time they hit).


The second is that there are alot of wrapping errors when a value exceeds what the type can accept. For example, an Unsigned Byte can have a value of 0 to 255, and the bug with Diablo is that often the values are larger than 255 and wrap around. Biggest example is Diablo himself. In Normal, Diablos To Hit is 220%, in Nightmare it is 44% (likely meant to be 300%) and in Hell it is 84% (likely meant to be 340%). Instead of his To Hit going up, it goes drastically down, since the value wraps around.

[PerfectFifth]

Does the famous potion dupe count?

Dupe any item in the game manually:

Drop the item you want to dupe on the ground. Walk a fair distance from the item, to allow for preparation. Click on the item. If you click on a potion in your belt PRECISELY as you pick up the item on the ground, the item will go to your inventory and the potion will become a dupe of the item.

NOTE: Later versions of Diablo will auto-delete dupes that are both on the ground at the same time. So don't drop them both.

[Kunzaito]

I have always been irked by a strange Battle.net bug. It happens mostly with the random health and mana potions you find littering the ground in the dungeons (not dropped by monsters, the ones that are just placed there) but it can also happen to the "treasure room items," the magic (and occasionally unique!) items that are pre-placed in enclosed rooms with gold and enemies (mainly in the Caves). Sometimes you will click the potion item, and nothing happens. Then you wait a few seconds, and... poof. Item is gone. Mildly irksome when it's a potion, enraging when it's a magic full-plate mail! Especially since you have to sit there and watch it happen, knowing what's coming once the item doesn't pick up, but powerless to stop it...

[Lanthanide]

The 'absorbs 1/2 trap damage' modifier, frequently found on rings but it is a low mlvl (so you need to hunt around in Normal church/cats for it) is bugged and actually reduces all damage from spells (and possibly projectiles like arrows?) by half.

Pretty sure that was fixed in Hellfire, and possibly in the later patches also.


Also not really a bug, but the monster activation radius (or 'aggro' as it's now so quaintly called) depends on your light radius, so items that reduce the radius can be considered 'better', even though they're technically cursed.

[Swiffer]

Oh, another fun one, you can still get knocked out of your own light radius by knockback, which can make things get very very dark indeed

[Phredreeke]

The 'absorbs 1/2 trap damage' modifier, frequently found on rings but it is a low mlvl (so you need to hunt around in Normal church/cats for it) is bugged and actually reduces all damage from spells (and possibly projectiles like arrows?) by half.

Pretty sure that was fixed in Hellfire, and possibly in the later patches also.

It still absorbs half of all spell and arrow damage in Hellfire. It was fixed in one of the D1 patches though.

Also not really a bug, but the monster activation radius (or 'aggro' as it's now so quaintly called) depends on your light radius, so items that reduce the radius can be considered 'better', even though they're technically cursed.

There's a bug though that makes monsters respond to the highest light radius you've equipped while on the level. Also golems have an infinite light radius and such will activate every monster on the level!

[Lanthanide]

Also golems have an infinite light radius and such will activate every monster on the level!

I'm 99% sure that is incorrect. I remember many times using Infravision to watch my Golem beat up nasties over the wall, and he would only ever go up to and fight 1 monster at a time, while all the others stayed where they were.

Perhaps this would apply after the monsters were activated? Like if the player woke them up, but then ran away, and a golem walked around the corner, they'd wake up again?

[Kunzaito]

I'm 99% sure that is incorrect. I remember many times using Infravision to watch my Golem beat up nasties over the wall, and he would only ever go up to and fight 1 monster at a time, while all the others stayed where they were.

Perhaps this would apply after the monsters were activated? Like if the player woke them up, but then ran away, and a golem walked around the corner, they'd wake up again?

I've read that the golem's aggro radius is sort of "partially" infinite - basically, enemies won't activate and swarm him, but ranged attackers sense and fire at him from any distance.

[Flux]

Every succubus on the entire level with a direct LoS to the golem will fire at him, but other monsters don't react in that fashion.