As with most encounters in the Firelands, Ragnaros requires two tanks no matter which raid size you're in. For healers, you should shoot for two to three in 10-man while taking five to six in 25-man. In many ways, less is more for Ragnaros, as it is with several other encounters. Healing is rough, but overall it shouldn't be that overpowering. In many ways, you need to push your healers just as much as you push your DPS, taking as few as you can get away with.
Overall position will vary throughout the encounter, but initially you will need to have the raid spread out across the room. Try to avoid using the far edges of the room at any point in the encounter, as there is a high risk of falling off the edge of the platform and into the lava below. During phase 1, this can be totally unavoidable, but in later phases, this should only occur if you make a mistake. Either way, it is far better to be safe than sorry.
A last important note before you even pull is that you need to have someone who can deal with falling from large heights. Rogues and druids in Cat Form are not enough; despite their reduced falling damage, they will still get one-shot. You absolutely must have either a mage or a priest. A paladin can also manage it, though a single paladin won't be able to do it all. Players with engineering also work, but again, you will need more than one. If you lack any of the aforementioned classes, then you're in trouble.
Unlike other encounter strategies, I will not list all of the abilities at the onset. Ragnaros is a long fight with three phases plus two transitions, each with their own ability set. All of the abilities that you will face in any given phase will be listed at the start of the phase. With that in mind, here is the first set of abilities that you need to contend with.
Sulfuras Smash Ragnaros faces the location of a random player and smashes his hammer down violently. Getting caught by the hammer will one-shot any player right out. Upon impact, the hammer sends out three Lava Waves.
Lava Wave Moves in a straight line across the map from the location of a Sulfuras Smash. Hitting a Lava Wave inflicts high levels of fire damage and leaves a last DOT for additional fire damage; also knocks the player back.
Wrath of Ragnaros Blasts the location of a random player, dealing light fire damage and also knocking back that player and anyone within 6 yards. Hits three players in 25-man.
Hand of Ragnaros Deals light fire damage to all targets in melee and knocks them back.
Magma Blast Blasts the current target with fire and increases fire damage taken by 50%. Only used if the current target is outside of melee range.
Burning Wound Ragnaros' melee attacks leave a fire damage DOT on the target. Players with Burning Wound attack with a Burning Blast, dealing fire damage with every attack. These effects stack.
Magma Trap Launches a trap at a random player's location. Getting hit by the landing trap inflicts high levels of fire damage and knocks the player back. Becomes activeated after landing.
Magma Trap Explosion Deals light fire damage to all members of the raid. The player who triggers the trap is launched into the air. Triggering a Magma Trap debuffs the player to take 50% additional damage from other Magma Traps; this debuff stacks.
While seemingly a lot, phase 1 is relatively simple for the most part. In general, players won't face much movement at all provided that you stand in prime locations. Sulfuras Smash is one of the largest threats of this phase and the entire encounter. Each Smash will send out three Lava Waves that travel in a triangle off the hammer; basically, one goes straight, one left, one right. Melee players shouldn't have to worry about Lava Waves at all, but they do have to be cautious not to get hit by the hammer itself. Ranged will have to deal with the Waves, which should be easily avoidable. The Waves move relatively slowly, and you have a good 10 seconds of seeing where they will travel before they even begin to move.
Wrath and Hand of Ragnaros are going to be the more annoying abilities that you'll suffer through in this phase. Their damage is relatively meaningless, as it's rather weak, but the knockback from either ability is super-annoying. More than annoying, it can be really dangerous for ranged players. Standing too near the edge or a Magma Trap can easily send you flying into it, which will result in your death. You need to avoid standing near any of these at all costs. Further, ranged players should avoid standing within 6 yards of each other, to avoid having multiple people hit by a single Wrath. One good thing is that Wrath can be totally resisted, avoiding both the damage and the knockback.
Last is the Magma Trap. The player targeted by the trap should move immediately to avoid getting hit by it; the Trap moves slowly, and there is plenty of time to get out of the way. Players should not merely get out of the Trap and sit there, however. Again, Wrath can knock you into an active Trap, so be sure that you move at least 6 yards away form the effect, even if you are the target of it or not. Magma Traps do not disappear; the only way to get rid of them is to trigger them.
The raid damage done by a Magma Trap isn't all that bad, but you should make sure that everyone in the raid, especially the tanks, are topped off before exploding one. Losing a player due to a Trap explosion sucks. As mentioned, only a few classes can handle triggering traps. Without some method of actively slowing your fall, you will die from the Trap. Mages and priests are best for this, but if you want to get creative, you can use other methods; they are extremely risky, though. Life Grip
on a player just before they land will save them, as will a Hand of Protection
. Similarly, a warrior is capable of using Intervene
just before landing to avoid fall damage. Those are extremely risky to use.
A single paladin is capable of handling up to two Traps on his own. They can use Divine Shield
in order to totally avoid the damage, and they can mitigate with Hand of Protection. In these situations, always use Hand of Protection first, as Divine Shield will drop the debuff left by the previous Magma Trap. Either way, having a single player release all of the traps can be rough if you don't wait for the debuff to wear off first. The debuff lasts 30 seconds, and a Trap comes around that time frame, sometimes a little earlier, sometimes a bit later.
Finally, tanks will get a stacking debuff from Ragnaros that deals increasing fire damage. This DOT is wicked-strong and will be a major source of tank damage throughout the entire encounter. Tanks should never take more than three stacks if they can avoid it. The good news is that Ragnaros spends a significant amount of time not attacking tanks. Sulfuras Smash is a good amount of time where tanks are not being hit, while there are only moderate delays from his other abilities. With good dodge, it is possible to reset your stacks.
Despite all that, this is a relatively easy phase. DPS should merely focus on Ragnaros, who's the only target, anyway. This phase will last until you bring Ragnaros down to 70%, at which point you enter the first transition. During the transition, Ragnaros will prepare to go back under the lava, but there is still time where you can attack him; at this point, put as much DPS onto him as you feasibly can.
Splitting Blow Ragnaros slams Sulfuras into the ground, inflicting massive fire damage to any player with 6 yards. Can target the right, left, or center.
Son of Flames Ragnaros summons up eight Sons of Flame that will attempt to reach Sulfuras.
Blazing Speed For every 5% of health above 50%, a Son of Flame will move 75% faster. Reducing the Son below 50% health removes this buff
Supernova Upon reach Sulfuras, the Son of Flame explodes dealing massive fire damage to the entire raid. Potentially one-shots nearly everyone.
Lava Bolt Ragnaros will send out bolts of lava to hit random players for light fire damage every 4 seconds.
Transitions are the first make-or-break portion of the Ragnaros encounter. The focus here is on high burst and control from all players. Healers won't need to focus much on healing during this phase, so any assistance they can add to helping take down adds is a huge benefit. Do not worry about slow effects, as they won't work against the Sons; however, stuns, knockbacks, and Death Grip do work.
The Sons have set spawn points depending on where the hammer lands. On the left or right side, there will be two spawns on the short side of the hammer, while the rest will spawn on the long side. One thing of note is that the two farthest adds will run through the lava in order to reach the hammer, making melee useless against them. Should the hammer fall in the middle, then the add spawns will be evenly split across both sides.
If the hammer falls on one side, then you absolutely have to have players able to stun the adds on that side; Death Grip works too, but a single knockback probably won't be enough. For 10-man, you should have one person on each of these adds, while 25-man should have two per add. That should be enough to take them out before they can reach the hammer. Stunning them early is more important, as once they drop below 50% health, their speed slows to a crawl.
For the center or on the longer side, the focus needs to be on those adds that are closest to the hammer. These should be stunned right away as well while DPS takes them down. Once again, it should only take a single player in 10-man and two in 25 to handle them. You cannot, however, totally ignore the farthest adds; otherwise, they will bum rush the hammer faster than you can react. You don't need to assign any control to them, but you should have a DPS working them down.
The largest thing to remember here is that killing the adds isn't entirely the point. While all of the adds absolutely have to die, slowing them down by dropping their health is far more important in the short term. Every add needs to drop below 50% health as soon as you can. For ranged players, any time your current target drops below 50%, you should switch to any add that is above that mark. Melee should not switch because they simply are not capable of catching up to an add that has more than 75% of their health.
Any death knights you have should focus on adds in the back first so that they can Death Grip anything that happens to get too close to the hammer, while any balance druids or elemental shaman should remain close to the hammer in order to knockback anything that starts to threaten the raid. Another tactic you can use in 25-man, should you have an abundance of death knights, is to Death Grip the two close adds back toward the farther adds, which will allow your group to AOE them all down instead of using a single-target approach.
The transition will end either when all adds are dead or after 45 seconds, whichever happens first.