Your character is eligible for loot the first time you kill a boss that week. You can still kill that boss on other difficulties or even the same difficulty but aren’t eligible for loot for that boss.
My guild clears Siege of Orgrimmar on Heroic (flex) difficulty. We still have time in our raid schedule and can start working on Mythic Immerseus. If we happen to kill him that week we wouldn’t get any loot.example 2:
My guild clears Siege of Orgrimmar of Heroic (flex) difficulty and we are done raiding for the week. My friend’s guild needs help with their Heroic run. I can then help them but wouldn’t be eligible for any loot that drops.
Loot drops scale with the number of players that are eligible for loot.
In Mythic difficulty if all 20 players are eligible for loot you will get 4 pieces. If 19 players are eligible for loot you would get 3 pieces and 80% chance of a 4th piece.
18 players eligible = 3 pieces and 60% chance of 4th.
17 players eligible = 3 pieces and 40% chance of 4th.
2 players eligible = 40% chance of 1 piece.
1 player eligible = 20% chance of 1 piece.
Ability to zone into any boss your character has ever killed.
My guild clears Siege of Orgrimmar on Heroic (flex) difficulty. The next week we are going to work on Mythic. Since we have previously killed all bosses on Heroic we can then start our week on any of the bosses we choose. We decide to start at Galakras and clear to Garrosh then start working on Mythic Immerseus through Sha. We couldn’t zone in to any boss other than Immerseus unless someone in our raid had previously killed another boss on Mythic difficulty.
Boss mount drops that drop 100% of the time require 80% of the raid to be eligible for loot. If the raid is at 80% but your character is locked the mount would still drop but you wouldn’t be eligible for it.
Boss specific titles. Instead of being tied to one boss it would be tied to all previous bosses also.
Hellscream’s Downfall. You would have to kill every boss in Siege of
Orgrimmar on Mythic difficulty to get this title not just Garrosh.
For this to work there would need to be some new or redesigned UI elements. Something to tell you which bosses you are eligible for loot for that week. Something that shows what percent of the raid is eligible for loot. And something that enables you to zone into any boss you have previously killed.
Also made a post on the WoW forums: http://us.battle.net/wow/en/forum/topic/12673548345
Feedback is appreciated.