Necro DoT stacking?
 

Is it true that necro Dot's stack? My buddy plays an Necro and I am looking to start an Ikky necro if this is true.

Yes. One each from your magic (darkness), disease (dc, heart flutter, etc), fire (blood line), poison, and leech line (lifetap over time).

I believe this was patched in to not work just like it was in classic. I haven't tried as a necro, but I know that 2 bards DoTs won't stack on the same mob unless something has changed with Kunark.

This is true.

However, if 2 necromancers try to cast the same DoT, the one from the lower level character, or the second one cast will not take hold.

i.e. 2 necs of same lvl cast splurt, the first one sticks, the second does not.
a lvl 52 and a 51 each cast splurt, the 52 will overwrite the 51.