Some magical weapons have additional Fire/Cold/Poison/Lighting damage added. It also can be added through runes and gems. What I do not understand are two things.
1. What does each kind of damage do?
Poison is obvious, deals damage over time. Cold slows the enemies, but the other two are unclear. Fire doesn't seem to do anything spectacular, lighting as well.
2. Why are there such differences between gem damage for each kind?
The best gem for each kind of elemental damage give the following:
- Ruby - 15-20 fire damage
- Sapphire - 10-14 Cold Damage
- Topaz - 1-40 Lightning Damage
- Emerald - 100 Poison Damage over 7 Seconds (14.3 dmg/s)
From this perspective Emerald looks way more powerful than other gems. I don't think the game would be so unbalanced, so I guess I'm missing something that would explain different amounts of damage.
So once more, the question:
Q: What are the advantages of each gem (elemental damage) with regards to the damage balance?