Welcome to our Ambush league mechanic guide, or in more common terms, our Strongbox league mechanic guide! Strongboxes have been part of the game for a long, long time, to the point they're barely thought of as a "league mechanic". Let's see what these fancy, dangerous chests are up to. We'll go through their many types, the dangers they may pose, and ways to get the most out of them through the Atlas Passive Tree.

Strongboxes are considered Extra Content and have a chance of appearing in any map area and most story areas; multiple Strongboxes may randomly appear in the same area, it is not limited to one.

Our league mechanic guides are structured according to "Depth" - the deeper you go into the article, the more complex the mechanics get. If it all becomes too much, take a break from this guide, play with the league mechanic enough to master the fundamentals then come back and delve deeper!

Difficulty: Generally easy, deadly if you find yourself in a flow state.
Complexity: None

The icon that denotes Ambush content.

Depth 1 - The Strongbox

You'll no doubt have stumbled upon a variety of Strongboxes throughout the campaign - perhaps you even found the secret passage that leads to the Chemist's Strongbox in The Upper Prison in Act 1! Certainly, you've got some idea of how they work, but let's start this guide nicely, with a recap:

• Strongboxes are basically a trap chest. You open it, and monsters spawn around it.
• Once all ambushing monsters are slain (they have a circle around them for easy distinguishing), the Strongbox opens and its contents drop to the floor.

Guess that wraps it up! Wrong.

Strongboxes, like other items in the game, come in different varities and in different rarities. Here's what you need to know:

• Strongboxes have several varieties that influence the type of loot they drop. We'll check this out in the next section.
• Strongboxes have unique modifiers that influence both the ambushing monsters, the Strongbox itself, as well as its loot.
• Strongboxes can be modified through crafting.

You can modify a Strongbox much like you'd modify a map, by using Orbs of Transmutation, Orbs of Alchemy, Orbs of Alteration, Chaos Orbs, Vaal Orbs and so on. You can even use an Orb of Chance and potentially upgrade it into a Unique Strongbox! Here's a few guidelines when crafting a Strongbox:

• It is generally recommended to spend currency crafting Strongboxes of the following types: Diviner, Catrographer and Arcanist. These are the most consistently rewarding ones.
• Using a Vaal Orb will Corrupt the Strongbox and make is unmodifiable, but also Corrupt some of its loot.
• Strongboxes can also get increased quality (up to 20%) by using Engineer's Orbs. Each one adds +5% quality if the Strongbox is of Normal rarity, 2% for Magic, 1% for Rare & Unique Strongboxes.
• Strongbox Prefix modifiers always increase the difficulty of the encounter, such as summoning extra monsters or casting a dangerous spell a couple seconds after being opened.
• Strongbox Suffix modifiers always change the Strongbox's loot, such as increasing the amount of items it drops or guaranteeing certain item types in the loot.
• If you find an Unidentified Strongbox, you can use a Scroll of Wisdom to identify it!

Let's take a look at the kinds of Strongboxes you'll generally encounter!

Depth 2 - Strongbox Types

We don't have the exact chance for a Strongbox to be of any particular type, but let's just say the regular 'Strongbox' is the most common, and all the rest show up less than 10% of the time. Check out the table below to see the types of Strongboxes, as well as the kind of loot they drop:

Note that some of these Strongboxes may also drop thematic Divination Cards. For example:

• A Jeweller's Strongbox may occasionally drop Hubris.
• A Cartographer's Strongbox may occasionally drop The Cartographer.
• An Artisan's Strongbox may occasionally drop The Master Artisan.

Depth 3 - Strongbox Prefix Modifiers

There's a whole bunch of them! Not all are dangerous, however, and you may even want to take some. First things first, though, here's a table of the mods you really just want to avoid, because they can be extremely lethal if you're not careful. Note that aside from the Arctic prefix, which is instant, the rest do take a couple of seconds for their effect to occur:

Now, it's not all bad. If you want to spice it up with a bit of reward, you should like the following modifiers, which give you more things to kill, for potentially more loot:

Depth 4 - Strongbox Suffix Modifiers

Let's talk about the good stuff! The mods you want to see! There's even more of those! Aside from your usual mods that increase the amount of items that drop, or their Quantity or Rarity (you'll see these a lot), there's others you'll want to look out for. Here's the juicier ones that can be rolled on most Strongboxes, including the most basic ones:

They're not so bad, right? Especially the Scarab one, which carries regular, Large and Ornate Strongboxes on its back right now. Let's see a few modifiers that can only roll on special Strongboxes:

Depth 5 - Unique & Special Strongboxes

Alongside the Chemist's Strongbox, which can only be found in that one secret room in Act 1 and drops a whole bunch of flasks, there's a couple more Normal / Magic / Rare Strongboxes you may come across. These are:

• The Operative's Strongbox, that can only be found in Alva's Memory of Cascading Fortunes (Memory Guide) and contains Scarabs of different varieties.
• The Vaal Vessel, which can be found in the Vaal Temple Map, accessible only by randomly Corrupting maps and hoping one transforms into it.
  • The map contains 10 Vaal Vessels.
  • They're all Corrupted and also spawn a miniboss of the type found in Vaal Side Areas.
  • They drop a whole bunch of items, all Corrupted, and quite often you'll find Unique items with two Corrupted implicit modifiers in them!

Unique Strongboxes

There are 12 Unique Strongboxes that may randomly spawn in your maps, or be transformed into by using an Orb of Chance on a Normal-quality Strongbox of the corresponding type. Here they are:

*The Maelstron Cell only has a chance to spawn in Shaper-influenced maps, or occasionally found after defeating Catarina if Haku is in the Fortification Safehouse and Rank 4 (Betrayal).

Depth 6 - More Strongboxes & Ambush Scarabs

Want even more of these deliciously deadly chests? Let's see how you can guarantee some in your maps:

• Using the Ambush map crafting option, which costs 7 Chaos Orbs, will guarantee 5 additional Strongboxes in your map.
• Using the Ambush Scarab will do the same! You can use up to 4 of these per map!
• The Twice Tempted Notable node on the Atlas Passive Tree will guarantee an additional Strongbox in all your maps.

In addition, there's a bunch of other Scarabs you can make use of in order to really go hard on this league mechanic. Note that any Scarab that does not directly state it adds Scarabs to the map, well, won't. You'll want to use one of the above options to make sure your Scarabs won't go to waste:

• Ambush Scarab of Hidden Compartments - Recycle the boxes!
• Ambush Scarab of Potency - Stronger Strongboxes, stronger Strongbox loot!
• Ambush Scarab of Discernment - Flip the table on their rarities and get more Diviner, Arcanist, Gemcutter (etc.) Strongboxes, and actually get some decent loot.
• Ambush Scarab of Containment - Wait, what's this?
  • This Scarab basically replaces every monster pack in your map with a Strongbox.
  • You'll be opening Strongboxes all the way up to the map boss.
  • This virtually guarantees you'll find some of the better Strongbox varieties.
  • Combining this with the Ambush Scarab of Discernment could have some interesting effects...

Depth 7 - Ambushing Atlas Passive Tree

later

Other Considerations