When you learn how to play more effectively any necro spec can be good.
Pet spec is a fine spec for pvp, but you have to learn certain things.
Currently I'm shatter/lich for Tier 2 raiding.
Rules for pet spec:
(Feel free to add some, if i missed any)
1. Terrain - Utilize this as best you can. Most classes can't charge you when you're on a weird shaped rock, so use that to your advantage.
2. LoS - When fighting casters as a pet spec use line of sight to your advantage so their casts don't hit you but your pets are constantly on them.
3. Effective Crowd control - Ice shackle won't break on damage, but freeze does, so if you freeze someone to CC them make sure your pets dont attack or the stun will break. If someone is running normal speed to you to use a combo, time your fear appropriately so that your fear goes off right when they're in range (takes some practice).
4. Kiting - Learn it. Love it. Making melee use stamina (void helps) will assure you're not going to get 1 shot (2-3 shot instead :P)
5. DoTs are your friend - Throwing dots on your opponent while you're kiting will help the "killing process."
6. Play "chicken" - Charge your opponent, sidestep and make it so they have to flip 180 degrees to keep attacking you, also gives you a little running room
If you want to add more, Use a number in front so I know ur not just commenting, thanks
