Diablo 3 is split into into four chapters known as Acts with each one having a specific overall objective as well as an end boss. Below is a description of all the Acts in Diablo 3.
Warning: This contains storyline spoilers! You have been warned.
This is where your chosen class starts out by going to New Tristram to find the fallen star. A brief rundown on what you will do in this Act, in sequential order:
- Protect New Tristram from the rising dead
- Rescue Deckard Cain from the Cathedral
- Find the crown of King Leoric from the crypts
- Kill the Skeleton King
- Retrieve the sword of Tyrael (the Stranger) that was split in three separate pieces
- Rescue Tyrael from Maghda
This act will have you explore New Tristram, the ruins of Old Tristram, the Cathedral, and King Leoric's old torture dungeon. You unlock the Templar and the Scoundrel followers during this act, as well as the Blacksmith. This act ends with The Butcher as the end boss.
This act is when you start your battle directly against the Lesser Evil Belial. Belial's influence has corrupted Caldeum, and so you must travel there to kill him. Here is a rundown of what happens during this act:
- Travel to Alcarnus to kill Maghda, while overcoming the obstacles she left in the way
- Rescue Adria (Leah's mother) from the sewers underneath Caldeum
- Resurrect Zoltun Kulle to get to the Black Soulstone by finding his head, blood, and body
- Kill Zoltan Kulle
- Kill Belial
This act starts out slow having you run in the desert, but it gets really interesting later on when get to Zoltun Kulle's archives. The end boss Belial is the best boss in the game in my opinion, as he looks like a proper Lesser Evil. In this act you also unlock the Jewler and the Enchantress follower.
This is by far my favorite act in the game. Basically Azmodan is invading Sanctuary from the ruins of Mount Arreat, and you must go to Bastion's Keep (the last stronghold between Mount Arreat and the rest of Sanctuary) and hold him back. Here is what happens in this act:
- Rally the troops of Bastion's Keep to regain their morale
- Raise the catapults on top of the keep
- Remove the demons that have infested Bastion's Keep's walls
- Close the breach in the basement of the keep, which was caused by Ghom
- Destroy Azmodan's war machines that threaten to destroy the newly saved Bastion's Keep
- Descend into Azmodan's lair and kill him
Defending the keep was really cool, but the best part is definitely when you get to cross the bridge to get to Azmodan's side. The monsters just keep piling up while you chew them with AOE. At the end of the act Adria betrays you and unleashes Diablo into Sanctuary, which brings us to the next act.
The newly freed Diablo (which now has the powers of all the seven Great Evils) has fled to the High Heavens to kill the angels once and for all. Tyrael opens a portal so you can stop him. This is the hardest act in the game and will prove a big challenge on the higher difficulties. Here is what you do:
- Kill the demons that have invaded the High Heavens
- Free Auriel the archangel of Hope
- Destroy Diablo's portals from where demons are invading
- Ascend the Silver Spire and kill Diablo
I was expecting more from the Diablo boss battle, and the ending didn't really cut it for me. But of course, nobody plays Diablo 3 for the storyline anyway, so it's all good.