First of all (and i keep repeating this all the time since i still see people not realizing this) I need you to realize that gw2 has different aspects of the game,that you,your class and maybe your team need to adapt towards with the build you are using.
Generally speaking:
-Pve exploring and leveling: anything works and is viable here…
-Dungeons: Might,fury,zerker gear, vulnerability is what you need, always at all times
-Pvp: depends on class and on role you wish to do in a match (specially when you create a team of 5 players)
-WvW: Depends if you are roaming alone, following a zerg, or commanding the zerg.
Now that you hopefully realize this there isnt much to say when we talk about warriors in dungeons (or any other class)
In dungeons you look for ways to deal a ton of damage in short amount of time, and maybe a few quick ways to “support” your team by applying fire fields, blasting them, applying might to party members, applying vulnerability to the boss.
One of the “meta” build would recommend using GS+ axe/mace
axe is a great weapon for damage, its skill No1 deals more damage than a gs 1.
With Axe/mace they can stack 14 stacks of vulnerability, they are also able to aoe knock down everything for 2 seconds and spam 1 for high damage (pay attention to your tripple chops final chop. a lot of players inerupt that part by casting another skill)
then switch to gs and spam 100 blades for tons of burst damage,followed by a cornered whirlwind, a few 1’s for further vulnerability stacks and then back to axe.
Longbow in dungeons i suppose is for pulling or holding a long lasting large fire fields that you or other players can blast for tons of might stacks.
If you go phalanx strength trait might stacks wont be any problem for the entire party…
Using sigils of might (i think its might?) when you swap between your gs and axe will grant you some extra might stacks as well
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