Let's summarize this in one post. Below are things that do work and things that don't work when it comes to sub-50 PvP.
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Things you do
*want*:
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- Anything that gives you elemental resistance, like resistance to fire etc.
- Anything that gives you a boost to your critical, both chance and damage modifiers are good. That includes Mundus effects like "The Thief" and "The Shadow".
- Anything that gives you critical hit resistance.
- Anything that gives you armor and spell penetration.
- Anything that gives you armor and spell resistance.
- Anything that increases weapon attack speed.
- Anything that increases movement speed.
- Any passive that gives you a percentage increase for something, like 2% more damage etc.
Armor
Impenetrable Uses Diamond. Increase resistance to critical hits by x.
Reinforced Uses Sardonix. Increase total armor and spell resistance by x%.
Well-fitted Uses Almandine. Reduces the cost of sprinting by x%.
Infused Uses Bloodstone. Increase armor enchantment effect by x%.
Divines Uses Sapphire. Increase Mundus Stone effects by x%.
Weapons
Powered Uses Chysolite. Reduce cooldown of enchantments by x%.
Charged Uses Amethyst. Increase enchantment charges by x%.
Precise Uses Ruby. Increase weapon and spell critical values by x%.
Infused Uses Jade. Increase weapon enchantment effect by x%.
Defending Uses Turquoise. Increase total armor and spell resistance by x%.
Sharpened Uses Fire Opal. Increases armor and spell penetration by x%.
Weighted Uses Citrine. Increase weapon attack speed by x%.
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Things that are
*useless*:
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- Armor buffs that increase your armor value. That includes "The Lady" Mundus effect(!).
- Buffs that increase health/magicka/stamina.
- Buffs that increase health/magicka/stamina regeneration.
- Any passive that gives you a fixed amount of something, like +50 armor etc.
Armor
Sturdy Uses Quartz. x% chance to avoid dacay when defeated.
Training Uses Emerald. Increase armor skill line XP with this armor type by x%.
Exploration Uses Garnet. Increase exploration experience gained by x%.
Weapons
Training Uses Carnelian. Increase weapon skill line XP with this weapon type by x%.