Naxxramas

Faerlina: Dispel the volley. Mind-controlling her Worshippers can cut off her enrage, but playing through it is also viable.

Maexxna: Free people on the wall using range, burn down adds, and keep the tank alive during the stun.

Heigan: Execute the Heigan dance by staying near the borders of the four zones the ooze spews from. Avoid lagging and losing track of steps. Casters must leave the platform while the dance winds up to avoid death. Move into the zone where ooze just came from, but stopping is required to move.

Loatheb: This is a heal check. Prevent spores from hitting the tank by burning them before they land. DPS should stand inside where spores pop. Healers have a brief window to cast before healing is negated.

Grobbulus: This is a kiting fight. Off-tank or burn adds. Only the tank should stand in front of Grobbulus. If infected, run directly behind him to the wall until the poison expires. Dispelling the poison will cause it to drop where you are standing.

Gluth: Requires hunters, mages, and plate wearers to off-tank zombies in the back, as they cannot be killed from full health. When decimate hits, slow zombies and burn them to prevent them from healing Gluth to full health. Use two tanks to manage his debuff.

Thaddius: The two sub-bosses must die simultaneously. Jump to the other side and group up under Thaddius. From the start, negative polarity is to his left, positive to his right. When polarity shifts, move to the correct side based on your debuff within approximately three seconds to avoid death and damaging allies. Melee and tanks can stand away from his feet due to his large hit box. If your debuff changes during another shift, move counter-clockwise to the other side. Avoid standing too close to players on the opposite polarity.

Gothik: Choose to either split the raid or stay on the living side (left side). With good tanking and ranged DPS, you can stay on one side and burn undead adds when gates open, avoiding melee range. If splitting, dead adds from the left become undead adds on the right. Paladins are valuable on the dead side, while rogues and other crowd control (CC) are useful on the living side. After a time, gates open, and Gothik engages.

Four Horsemen: Split into four groups, with a healer and tank pair in each corner. DPS should be in the lower left and a few in the lower right upfront. Burn the first boss, then lower corners switch bosses. DPS burns the second boss, followed by another switch, until both front bosses are down. In the back, split DPS and watch debuffs to avoid stacking to 3 for each boss by staying close. Switch sides periodically. Watch void zones and alternate positions.

Kel'thuzad: More healers and less melee are preferred. The first phase involves killing adds from the middle. Once adds are down, KT activates. Melee should spread out away from the tank, and everyone should spread. Frozen players need healing, and mind-controlled targets require CC. Near the end, KT summons guardians that need to be off-tanked. This is a heal check.