With Warlords of Draenor coming up and the ability to have gear change primary stats (and set bonuses) depending on what spec a person is in it will make spec swapping much easier. This means it becomes easier to have more or less tanks or heals per fight without everyone gearing up and carrying around 2 sets of gear. In a discussion of future ideal raid composition for Orcbusters, my raid team, I stated that I could imagine fights ranging in needing between 0-3 tanks (or very unlikely 4). This led me to thinking of what a tankless fight would look like. Barring a PVP like event, which @Watcher quickly pointed out, what could be done?
So with the disclaimer that IANAGD (I am not a game designer) (yet) and that this is a very rough sketch, this is what came to mind.
normal & heroic would have mechanics that require position the boss in various places throughout the room, and keeping the boss in particular places at various times. This would be done in the normal tank manages boss positioning mode.
In Mythic however threat would not be generated in the normal fashion. Perhaps it could be triggered by a debuff, say one called mystic salad bar, which is randomly cast on melee and ranged players.
When the person has this debuff their attacks generate aggro. Positioning the boss is managed by using the debuffed players threat. Threat could be generated by dps while under the debuff (which seems very rng/crit dependent) or could be by stacks generated by number of attacks (etc.).
To avoid squishing players, the first few attacks to hit a ranged player will be weak and then ramp up in damage.
For melee players, if they stand in place* they get additional shielding to allow them to hold the boss for x length of time.
This allows the boss to be moved by range and then held by melee in the specific locations where they are needed. To drop the player off the the threat table the debuff needs to be dispelled.
So why do something like this? Because it is different. I find it interesting to have a fight that breaks up the usual Tank/Heals/DPS Trinity. Yes it still uses the threat mechanic but in a different way. Also while it does require positioning I think this is different than a “kite the boss” kind of fight.
I am sure there are other ways to implement a non PvP style 0 tank fights, but this is the idea that came to me this evening.
*this prevents the best strategy from being a stack all melee and kite as needed fight