Hello guys,
I tried to search, didn't get any results, and I doubt this is only client side. Well here's the trick.
1) Find a Monster NPC/ Player.
2) Click on him, and start casting anything i.e. Frostbolt.
3) While casting spam Right Mouse Click on him (simulates attacking)
4) You'll notice the skin (or however it should be called) of frostbolt didn't appear ,
however you did damage. If this isn't just Client side, it could help shooting people and run away untracked ;-)