Abrogator and WoD Drops: some misinformation going around especially since LFR launch, so here's how it works

LOCKOUTS : Every week you can

• Do as many LFRs as you want (No Lockout / it doesn't stop you)
• Do as many Normals as you want (No Lockout / it doesn't stop you)
• Do as many Heroics as you want (No Lockout / it doesn't stop you)
• Do Mythic with ONE group (old school Lockout / stops you going with a different group)

LOOT : You can get "A shot at loot"

• From all 3 LFR bosses (will increase to all 7 bosses when the other wings open)
• From all 7 Normal bosses
• From all 7 Heroic bosses
• From all 7 Mythic bosses

For a total of 24 "shots at loot" this week, and up to 28 when all wings open.

What about Abrogators (legendary quest drop)?

• You get one chance per boss, per week - no matter the difficulty.
• This means no more than 7 chances at Abrogators this week.

A shot at loot can mean a chance at Personal Loot or you were eligible for loot drops when the boss died with loot set to Need before Greed or Master Looter. Your "shot" is used up whether you won loot or not.

In the case of Personal loot the die was rolled (I don't know the chance, maybe 20% or so?) and if you didn't get loot the die will not even roll (0%) next time.

In the case of Master Looter if loot drops on a re-kill (same boss, same difficulty) the master looter will not be able to assign it to you.

Example

1. You do LFR this week and kill 3 Bosses - You get a 'shot at LFR loot tables' on each of the 3 bosses. You also get either an Abrogator Stone or an Abrogator Stone Cluster from each boss.
2. You then raid with your guild on normal mode, and kill the first 4 bosses. - You get a 'shot at normal mode loot' from all 4 bosses. You get no Abrogator Stones from Kargath, The Butcher, and Brackenspore, because you killed them in LFR. You get an Abrogator Stone or Abrogator Stone Cluster from Tectus.

Edit: Thanks to u/Breimann for linking the gator. u/codylllamos explains the Mythic lockout system.

Edit2: Changed to it u/Ded0099 explanation on the abrogator stones, and expanded example.