I primarily play mesmer, and they really are not as op as everyone is saying, and all theese threads about mesmers are getting annoying so heres some tips and tricks of the top of my head.
Classes with pets:
Allow the mesmer to attack you first, your pet will insta attack and agro on the original mesmer, watch for it, hit ctrl+t, that is your target.
Engineers:
Grenades. Grenade spam will wipe out all clones near instantly, probably one of the best counters against mesmers, and also flamethrower, all the clones will be nicely grouped for you.
Everyone:
Get out of LoS (line of sight) all the clones will run after you, leaving the mesmer singled out. And there is lots of ways to do that.
Ele:
AoE spam, same as engis. then ctrl+T the mesmer. (good for mesmer patrol)
Warrior and melee
Work with an aoe class, as soon as you see them wipe out all the clones, a good fast aoe class will know when they have done this, get ready to stun,knockdown,immobilize the target, by this point they are usually nearly dead, or at least panicking making them easier targets.#
Pull out a bow, and aoe his stack of images, they drop sokittenfast its unreal, they literally do die in 1-2 hits max. Pull out a sword and spam the melee button, if you just took half health of the mesmer, it aint him, move on.
Get an axe offhand and use the crazy aoe spin and move
Actual structured team:
Have 1 person on mesmer patrol (yes i had people doing this last night) and get them to specifically focus on nothing but the mesmer. There primary job is to ctrl+t the mesmer, pressure the hell out of them, but not to kill them. That is a secondary objective. If you can keep the mesmer busy on you, that gives the rest of your team to breath.
Depending on mesmer weapons:
This may differ slightly, but if im carrying a staff, im running a clone build and defensive so expect lots of clones NOT phantasms, get AOE on to the mesmer lookout.
Sword and pistol. Watch for that sudden melee mesmer on you, if you see it, ignore it, the other phantasm out is a ranged dps phant, that leaves only 2 (if mesmer has a clone out) targets.
If a mesmers clones and phantasms run at you, be very cautious of the debuff on you. Especially confusion, this can screw many fast paced classes up because you are damaging yourself every skill you use.
Downed state:
A mesmer has a RED ARROW, above there head, a cloned down does NOT. Just look for the red arrow over the mesmer when they are downed, that is your target.
If you are 1v1 against a mesmer, and not fully sure you will win, or getting annoyed RUN. Just run away, its FAR better than waiting to respawn, and your time on the field will increase dramtaically.
Contribution from Sjach Darasv:
Another tip, if you see the mesmer spawning out the phantasms, the pale pink see through ones, kill them. They take 2-3 hits at most to kill and they will be doing 75%+ of the damage you receive, the mesmer himself in this case cannot spam them as fast as a clone mesmer and will usually have less abilities to create clones than a mesmer that uses clones to do damage or clones to pop the f1-4 various abilities for conditions or bursts.
If i think of any others i will add them, or if you have any questions on a certain event or time when you have troubled, ask me and i will answer.
(edited by Spider.3486)