[Caden]

If you're going to play a bone necro, you're going to have to master 5 of the 6 bone skills. Particularly, Bone Spear, Bone Prison, Bone Wall, Bone Spirit, and Teeth. Your bone skills won't do much damage if you don't. Then you will need to put 1 point into clay golem and golem mastery. The golem can slow down enemy players that it hits and can take the blow of oncoming homing missles. Then you'll want to look into getting Decrepify and maybe Lower Resist. Lower Resist will only be useful when playing with other players who use elemental magic so LR isn't necessary for you to get. Then, I guess you could put 1 point into Revive and Summon Mastery. Though, you may not want to get Revive. You'll mostly want to master those 5 bone skills. 1 point into Decrepify is all you'll need with all the gear you get to increase your skills.

Bone necros aren't very affective against monsters in 8 player games. They are very, very effective in pvp, though. Summon Necros are the most effective build against monsters. Poison Necros are somewhere in between.