Crumbling Vault - Event Guide - Diablo 3
This guide will cover the Crumbling Vault event in Diablo 3, providing information on how to complete and find it. Events like this are essentially small mini quests that often provide gold, experience and sometimes item rewards for completing a short task or series of closely related ones.
Finding the event
This dungeon and event is a random spawn in the Stinging Winds region of Act II. There are four spots in the Stinging Winds which can spawn one of set of three dungeons, the Crumbling Vaults, The Chamber of the Lost Idol or The Ruins. You can see the four blue dots on the map to the left which represent the four possible locations the set can spawn at.
The quickest way to run this area for the vault is to take the Khasim Outpost waypoint and run each path drawn out in the map picture to the top right one at a time, checking the 2 spots on each path. Use the town portal when finished running one path, then use the town waypoint to head back to the outpost and run the second. If at any point during your search, you run across the chamber of the idol or the ruins, you can stop your search and make a new game to try again, since you will only ever find one of those three in any given game.
If you are successful you will find the Treasure Hunter standing outside the vault, whom you can talk to to start the event.
There is an achievement for completing this event and another specifically for doing so in co-op.
The Crumbling Vault
"Once in a thousand years, when the stars align, these ruins open, but only for a short while. There is treasure rumored to lie deep below. Find it fast, or die when the dungeon seals itself for another age."
Before entering the vault, you will need to prepare yourself as this is a timed event, meaning you'll only have about couple minutes at most (2:30 on hell, changes for other difficulties) to find the Treasure Room which is somewhere at the end of the randomly generated level.
Next you will need to solidify your purpose here in your mind. Are you here to kill monsters and loot them, or reach the treasure room and loot the chests? It may not seem like it, but this event presents an intriguing psychological challenge for the Diablo player who is used to the constant killing and looting. Unless you are a high enough level to insta-plow the enemies on a much lower difficulty, you will not have time to stop and loot what you do end up having to kill. If a unique drops however, it may be worth the potential loss of the run to retrieve.
Try to go in with any skills which can slow, stun, knockback or otherwise assist with your mobility, as they will be immensely helpful. Damaging skills with little or no cast time that you can use while moving are invaluable as well. This would also be a good time to equip any boots with +movement speed.
Find the Vault Treasure Room
As soon as you enter, the timer starts counting. You will have a lot of ground to cover and some of your chances here will be also based on luck considering the limited time and plethora of enemies. Dodge what you can, but try to leave some area of effect or mass dot spells (like locust swarm) to cut away at the health of whatever is chasing you. This way if you need to double back you can cut through the potential wall of enemies that may be blocking you in a bit easier.
The only time you should stop and fight is to lay out your heaviest damage dealing attacks, or anything with knockback to quickly open a path that is closed to you. Only take time to kill enemies, especially elites, if you feel you absolutely have to. Taking out the Guardian Towers as you pass them, if you can manage to one shot them is a good idea as it keeps them from spawning new hordes to hinder your progress. Keeping your fingers crossed (in your head) that you don't encounter any Jailer or Walling elites or champions is worth a shot to.
Most of the above time sinks are unavoidable, which is why loosing more time by doubling back or stopping to pick up items will likely cost you the run. If you die at any time during the event, the timer will pause until you respawn, but you'll be back at the beginning also probably costing you the run.
If you've done well and have a bit of luck on your side, you will come across the room which holds the portal to the Vault Treasure Room, which is distinguishable by the layout and size, which is almost exactly like the room which you start the event in. Traveling through the portal instantly completes the event and sends with an experience and gold reward and puts you in the treasure room, where several chests, including one resplendent, await your looting. Make sure you use the fortune shrine that seems to always be here before opening the chests.
Unfortunately, the way back into the Crumbling Vault is sealed once you reach the treasure room, leaving no way to go back and loot it.
Protip - Looting Both Rooms
The following tip to loot both vault and treasure room is confirmed to work. Thanks for confirming this goes to Kamisama.
If you bring a second player one of you should be able to stay behind while the other goes through the portal into the treasure room. Once this happens, the original entrance to the Crumbling Vault becomes an entrance to the treasure room instead. If the player in the treasure room portals out before looting the chests and uses the banner in town to travel to the player who stayed behind, they should be able to loot and finish killing the monsters that remain in that now otherwise inaccessible area. Once finished there, they can portal back out again, use the outpost waypoint and enter the vault from the original Stinging Winds entrance to loot the chests together.