Beleriand, Westernesse, Ancient Dwarf-make: Damage Types Explained.
One of the most commonly recurring questions revolve about weapon damage types and where to get a particular damage type. This isn't an academic issue - both The Blind One and The Mistress of Pestilence are 100% immune to common damage, and harder instances hinge on you doing the best damage you possibly can.
First, there are no hard and fast "this damage type is best" rules, but rather a set of strong guidelines. This is aimed at the legendary weapon-wielding character - at pre-50 levels, just switch weapons.
1. Common is weakest. As an LM, I've seen that mobs resist common damage better than everything else, nearly all the time. So while you won't see it, it diminishes your damage, and that penalty is multiplied when you critically hit. Want big Heartseeker damage? Avoid common. Want to win sparring matches? Check your own resists, and see how much common resist you have. It's the highest of all types. Bottom line: Don't use common.
2. Common can be better than you think. With a slayer title scroll (Uruk-slayer, Dead-reaver, etc.) you will be doing a notable amount more against a very small subset of mobs. While in Moria, where it's orcs all the time, this might have been useful. For particular instances (think Skumfil with spiders, or Dark Delvings with ancient evil), it may be a good way to go, at least early on. But with the variety of opponents in Mirkwood, less so. Bottom line: Use Uruk-slayer in Moria until you can get something better.
3. Beleriand is effective against many mob types. All Ancient Evil creatures (Nameless, Morroval, Gaunt-men, Grim) suffer from extra vulnerability to Beleriand. So do Half-Orcs, Spiders and Insects, and for some reason, Wood Trolls. It's still good compared to common on nearly every other mob, but won't blow you away. If you want to get one damage type to stick with for a long time, it's Beleriand. Bottom line: Get Beleriand.
4. Fire is effective against many mob types. Creatures of Nature, Gorthorog, Snow-beasts, Trolls, Kergrim, siege engines, fumaroles in DN. Like Beleriand, it's good compared to common. Bottom line: Hunters and Wardens should always have some fire-oil handy.
5. Light is effective against many mob types. Unseen, Goblins, Orcs, Pale-folk, Trolls, Spiders. Like Beleriand, it's good compared to common. Bottom line: Hunters and Wardens should always have some light-oil handy.
6. Westernesse and Ancient Dwarf-make are extra effective against very few types, but sometimes are required. Westernesse is for fighting The Dead and Unseen. Ancient Dwarf is for fighting drakes/dragons. In Sarnur, you'll need Ancient Dwarf to get past the "Great Protection" buff on many of the creatures there, or you'll be doing ~10% damage. Only good compared to common. Bottom Line: Unless you're fighting in one of those areas (or perhaps against Thorog), these are only good until you can get Beleriand.
7. Beleriand or Westernesse plus slayer titles FTW! Get the increased damage output and a better damage type with these combination damage typescrolls. Everything you want, nothing you don't. They're cheap enough that you should look to maximize for particular raids, and settle back into the one that works for your daily PvE existence. Bottom Line: You need one of these.
8. Bosses can break all the rules. If it's got a name, it's worth having a LM check it out. Some bosses flip the resistances, others play right along. Bottom Line: You _DO_ have an LM along, right?
So, where do you go for these and what does it cost?
Damage types + Slayer
Slayer Titles (Tier 3 Common damage bonuses, all need infused adamants)
Fire-oils, Light-oils - These temporarily convert your weapon damage to the type of oil applied. If it was Ancient Dwarf-make before, now it's fire/light. If it was common (to include slayer titles), it's now fire/light. If it was Westernesse + Beast-slayer, now it's fire/light. Will need to test to ensure that the bonus slayer damage is gone, but it probably is. See your favorite scholar.
Beleriand, Ancient-Dwarf, Westernesse shield spikes - See your favorite weaponsmith. Guardians/Wardens - doing more damage should equal more aggro, but not knowing all things tank-ish, I'm not knowing how much. If you are using a shield attack on a common-immune enemy like the Mistress of Pestilence or The Blind One, look into a set of these spikes.
Finally, some lore for those of you into that sort of thing:
Beleriand: The Elves of Beleriand waged their wars against Morgoth in the First Age and are the most powerful of all the peoples in ancient crafts. (these are Turbine's words, my emphasis.)
Ancient Dwarf Make: Of all races the Dwarves were the most cunning at fighting off dragons. They had to be since so often dragons would seek the halls of dwarves for the great treasures which the dwarves would accumulate.
Westernesse: The Dead come primarily from the race of man, and the men of Westernesse were the most skilled of all at fighting this particular kind of evil.
Hope this answers some questions.
Raid Boss types: