Guild Wars 2

Both Necromancer Scepter and Mesmer Scepter have an effect on the third hit, Necromancer applies a poison and Mesmer summons an Illusion.

Mesmer can cast other abilities between the 3 Scepter attacks and the game remembers and still casts the Illusion after the 3rd attack. However; Necromancer must cast 3 continuous and uninterrupted scepter attacks to get the poison off of the third attack.

Bug? Intended?

Dealing dmg with another skill will interupt the chain.

And Mesmer Sceptre is slightly bugged, you can go through their chain w/o hitting anything. You can auto twice just before engaging a fight to open with a clone.