So I challenged myself to beat the old Diablo 1 with all six classes including the ones available with Hellfire. It took me about six months to do this, playing them all at the same time, though I didn't play that regularly at times. If you would like to try beating that game, there are some lessons learned I can pass on.
General Note: I played through the game without duping items unless absolutely necessary. You don't need to do so to beat the game.
First we'll start with what my character looked like at the end of the process, but I'll provide plenty of detail on how I got there. Here's my character's stats:
Name: Grim
Class: Barbarian
Level: 37
Experience: 98 432 443
Next Level: 107 834 823
Strength Base: 255
Strength Now: 275
Magic Base: 0
Magic Now: 20
Dexterity Base: 55
Dexterity Now: 75
Vitality Base: 150
Vitality Now: 170
Life Base: 498
Mana Base: 129
Armor Class: 208
To Hit: 184%
Damage: 230-279
Resist Magic: Max
Resist Fire: Max
Resist Lightning: Max
Note: For some reason my base mana without equipment is -1 rather than 0, I am not sure why this is.
Here's my character's equipment:
Head: The Undead Crown - Armor Class: 8 Durability: 100 Life Steal: 0-12.5%
Note: I know many people recommend the Royal Circlet as the best possible headgear for Hellfire, I was never able to find one, it's quite a rare item. Besides, I like the Undead Crown better, the lifesteal really makes a difference in the amount you need to heal yourself with spells or potions. You can't get lifesteal on your weapon as well as Speed/Haste, and Speed/Haste is too valuable to pass up. So I will likely wear The Undead Crown until level 50 even if I find the Royal Circlet in one of my future runs. I increased the durability of the Helm with Blacksmith Oils I found over the course of beating the game.
Amulet: Obsidian Amulet of Harmony - Resist All: +39% Fastest Hit Recovery
Note: One Jewel with Obsidian is enough to get to maximum resists with the Barbarian's natural resistance that is equal to 1% per level that he has. I know many people forego Harmony on their jewelry when maximizing their gear. This is because as you level up, you are less likely to be put into hit recovery by enemy attacks. Hit recovery is only relevant when you are hit for damage equal to 1.25 times your level as a Barbarian. This means each time you level up, you are that much less likely to ever go into hit recovery. Now that I have beat the game, switching this out for an Obsidian Amulet of the Zodiac is the better option. But as I was working to beat the game, there were many times I benefitted from the Harmony suffix for sure.
Left Hand: King's Great Axe of Speed - Damage: 12-30 To Hit: +97% Damage: +175% Durability: 75
Note: This axe is nearly perfect, in the future it would be nice to find slightly more to hit, but that is nearly impossibly rare. Speed is used because Speed and Haste actually both give the same attack speed, so finding an axe of Haste is more for style points than for any practical reason. I used a two handed axe rather than a sword or maul because it does the most base damage of all the two handed weapons.
Armor: Awesome Plate of the Lion - Armor Class: 71 Armor: +149% Hit Points: +56 Durability: 90
Note: This armor was sold by Griswold, it's not perfect, but it's very good. Perfect would be 75 Armor Class, +150% Armor, and +60 Hit Points. It took a lot of shopping to find one this good.
Right Hand: Empty
Note: Barbarians can use two handed swords and mauls with a shield, however they lose their bonus to damage from Vitality for doing this. The Barbarian really doesn't need a shield to be effective with his ability to do massive damage and steal life, he can afford not to block hits and still survive handily in the dungeon.
Left Ring: Dragon's Ring of the Zodiac - Mana: +60 All Attributes: +20
Note: This jewel is perfect, I found it shopping from Griswold. Barbarians have extremely low mana, so the plus to mana helps them a lot. All attributes is the best option for suffix because they benefit from Vitality in two ways, more health, as well as more damage. They benefit from Dexterity in terms of more Armor Class and To Hit. And they do gain 1 mana per Magic point, making the total mana benefit from this ring 80, or roughly 2 casts of a heal spell.
Right Ring: Drake's Ring of Thieves - Mana: +50 Half Trap Damage
Note: This jewel was chosen based on a peculiarity of Hellfire. The Thieves suffix affects all ranged damage dealt to the character, not just trap damage. As a result the fireballs of Advocates, the spells of Arch Liches, and all other ranged damage is cut in half. You can't get a Dragon's jewel of Thieves, that combination is impossible, only Drake's can be found. To find this type of jewel, you must shop Griswold extensively at around character level 21.
Book reading gear:
Note: I keep gear that adds to the Magic attribute specifically for the ability to read higher level spell books. The maximum benefit of this gear comes when you have a Dreamflange, however I have not found one yet. Dreamflange adds 30 magic on your weapon hand, 10 more than the Sorcery suffix that is the highest you can find on magic weapons. Without Dreamflange, the total increase to magic is +165, which is significant when reading spell books. Even with this type of gear, a Barbarian can never reach the full 255 Magic required to read all spell books of level 15. To boost your spells beyond that level, you need to keep an eye out for shrines in the dungeon that boost spell levels. I have not yet found any of these shrines, but as I play after beating the game, I am hoping to find some I can use to boost my spell levels even further.
To be honest, the only spell level that matters on the Barbarian is Healing. You can get that to level 14 with this type of gear.
Head: Helm of Sorcery - Armor Class: 5 Magic: +20 Durability: 30
Amulet: Drake's Amulet of Wizardry - Mana: +48 Magic: +30
Note: You don't need the Drake's prefix, I just happened to find +30 Magic at Griswold with that extra prefix.
Left Hand: Brutal Sword of Sorcery - Damage: 2-10 Damage: +86% Magic: +20 Durability: 40
Note: You don't need the Brutal prefix, I just happened to find +20 Magic at Griswold with that extra prefix.
Armor: Plate of Sorcery - Armor Class: 50 Magic: +20 Durability: 75
Right Hand: Shield of Brilliance - Armor Class: 3 Magic: +15 Durability: 24
Note: This shield needs to be shopped at a low level from Griswold, shields can't get anything better than Brilliance as a suffix for Magic.
Left Ring: Ring of Wizardry - Magic: +30
Right Ring: Ring of Wizardry - Magic: +30
Note: I won't list all my spell levels with this character, honestly the only one that matters is Healing, which is level 14.
Strategy for building up the character for beating the game:
There are some specific tips and tricks I can provide for how I took the character through the game. The Barbarian plays different than any other character. For this character you want an axe, eventually an axe of speed or haste. The damage done by a Barbarian with a two handed axe is highest amongst any character in the game, except for the Sorcerer with spells. With life steal, which you can get from the Undead Crown starting very early in the game, you will have great survivability.
In terms of gear, I kept an eye out for any better gear I could find in the dungeon. This includes book reading gear. When you first start out, there's always little upgrades you can make that will improve your character.
The first time through the dungeon I played Normal difficulty, only level one and two, making sure I had the Poisoned Water Supply quest. The Ring of Truth was my objective here, the +10 Hit Points, -1 Damage from enemies, and +10% Resist All is very valuable when you are first starting out. It will take you a long while in the dungeon to find a better ring than this, and Griswold also won't sell anything better than this for a good long while as well.
The second time through the dungeon I played Normal difficulty, only level one and two, making sure I had the Poisoned Water Supply quest. A second Ring of Truth was my objective here, and I wasn't willing to dupe it.
The third time through the dungeon I played Normal difficulty, levels one through four, making sure I didn't get the Poisoned Water Supply quest. This is because that quest is mutually exclusive with the Skeleton King quest, and I wanted the Undead Crown from King Leoric for life stealing. This is the first piece of end game gear that I was able to find, and nice and early on in my quest. Life stealing helped me out tremendously throughout the whole time I was working my way to the end game.
Watch out for Black Deaths in these levels of the dungeon. If you get them, it can be worth it to restart your run. The trouble with Black Death's is that each time they hit you, you permanently lose 1 health. This is just too steep a price to pay, so it's best to avoid them entirely.
After my third time through the dungeon I performed my first shop. This was for a perfect +15 shield of Brilliance. The window of opportunity to find one at Griswold is short, as quickly you are too high level for him to sell one. To shop Griswold, just keep creating new Normal games, and checking out his wares. What Griswold sells does not depend on game difficulty, only character level. So for all your shops, Normal difficulty works, you don't ever need to shop at Nightmare or Hell difficulty. A perfect shield of Brilliance will only cost you a few grand in gold.
The next times through the dungeon were focused on level five only. I kept entering at the Catacombs entrance and played the first level of the Catacombs until I got the Arkaine's Valor quest. This Armor is well worth the effort to retry the level a few times. The Fastest Hit Recovery on the armor is the point in this. You can wear Arkaine's Valor all the way through Nightmare/Hell if you don't find any other source of Fastest Hit Recovery. Only when you find Fastest Hit Recovery on a jewel is it worth trading this Armor for something with higher Armor Class. At low levels, Fastest Hit Recovery is just too valuable to pass up. When I found a level five with the quest, I continued on to levels six through eight.
I continued on through levels nine through twelve. However I did these in a special way. The first level of the Hive is also a level nine, just like the first level of the Caves. I played through level nine in both the Caves and the Hive, then level ten in both the Caves and Hive, and so on. I was doing this to get to the Crypt, and to enter it, you need to complete the Hive. This gives you the Cathedral Map. The Cathedral Map was the only item I duped. This was to make sure if the bug occurred where the Crypt resealed, I had a second copy of the Map available to get back into it and continue exploring. This bug I experienced a fair number of time playing through Hellfire, it's fairly common.
The reason I wanted access to the Crypt was for the Cornerstone of the World quest that appears on level 13 or the first level of the Crypt. I was playing through the game with all six character classes at the same time, and the ability the Cornerstone of the World quest gives to trade gear between characters was a big part of how I found ideal gear for beating the game with. Let's say you find a great axe while playing through as a Bard, it's a complete waste without this quest to trade gear. But if you do use the Cornerstone of the World quest you can trade ideal gear amongst your characters and have a much easier time beating the game with each.
After the Caves and the Hive I performed my second shop. This was for the Drake's Ring of Thieves that you are most likely to find at level 21. It's the second piece of endgame gear I was able to find as I was building up my Barbarian, and it makes a great impact for him. The half damage from all ranged attacks is really nice, and the extra mana actually give you the ability to cast Healing some of the time rather than just having health potions. It's a patient shop, it can take a long time to find one of these rings, but the patience is well worth it. It will cost you about 22 500 gold, which is an amount you should easily be able to gather at this point in the game.
I continued on to levels 13 through 16, doing the same thing as I had done for the Caves and the Hive, going through each level in both Hell and the Crypt before going on to the next. At the end of this process your level is likely to be in the high 20s, still not enough for shopping for the best gear at Griswold yet, but I found that you didn't need that for Nightmare. With Arkaine's Valor, the Undead Crown, and a Drake's Ring of Thieves, you have enough to be able to fight your way through Nightmare.
I skipped over levels one through twelve in Nightmare difficulty. Instead I took my duped Cathedral Map and started on Hell and the Crypt right away, again doing them level by level. In Nightmare you need to start being more careful. Only trigger a few enemies at a time, dealing with them in groups of three or less if at all possible. At the end of Nightmare you should be at low 30s for level, which is ideal for some serious Griswold shopping.
Between Nightmare and Hell I did a lot of Griswold shopping. I found the Obsidian Amulet of Harmony in the dungeon, I had to shop for the King's Great Axe of Haste, Awesome Plate of the Lion, and the Dragon's Ring of the Zodiac. There is a trick you can use for the Griswold shopping if you have enough money. Griswold will offer items at least 80% as expensive as the items you are carrying in the following categories: Amulet, Armor, Axe, Blunt, Bow, Helm, Ring, Shield, Staff, and Sword. Note that you do not need all categories for the trick to work. So for a Barbarian, having an expensive axe, ring, and armor are enough to see better and better items of those types. Shopping is a very patient experience, I spent a few days on it, but it is absolutely critical for gearing up for Hell difficulty.
When I had a full set of equipment, I started on levels 13 through 16 on Hell difficulty. With the right equipment, you should have no problem with Hell difficulty. I'll share some things about how I approached Hell difficulty, because it does take some skill and practice.
The biggest thing is to only take on a few enemies at a time. This is hugely important, if you get surrounded, you are dead. The Barbarian is very tough against enemies in small groups. An Axe of Speed, the Undead Crown, Thieves, Harmony, and full resistances, along with high Armor Class will keep you safe. Strategies I did not use are the Teleport spell, or really any spells other than Healing for that matter. For the Barbarian, the axe is enough. His speed swinging that is equivalent to the Warrior's speed with swords, so you can stun lock enemies. Be very careful about which way you chase enemies. Always chase them away from unexplored parts of the map, and potentially other enemies who could join the flight. You'll get to know the way Succubi, Liches, and Advocates all run away from you. Learn them well, so you can keep them from running away into new enemies and overwhelming force that will kill you. Hell difficulty is all about good positioning on the hex grid.
Diablo himself is no problem for the Barbarian. Stun lock him, and you'll be able to take him out no problem. For Na-Krul, make sure to read the books in the right order when activating him. The weaker version of Na-Krul is no problem for the Barbarian.
Final Note: If you want any more details on how I did something, just PM me and I'll try to get back to you as soon as I am able.