
We've just released the Crucible Mystery Box, which follows the same model as the Kalandra and Sentinel Mystery Box, with no duplicate microtransactions! Each of the microtransactions in this mystery box has visual behaviour that interacts with your gameplay.
There are 20 microtransactions that you can find in the Crucible Mystery Box. Each of these microtransactions has a varying number of thematic variations, and you'll never receive a duplicate copy of a variation that you have already opened. For example, if you open one variant of a microtransaction, you may later receive another variant, but you'll never get a duplicate!
Because of the lack of duplicates, each box you open implicitly increases the chance of opening the remaining microtransactions you haven't received yet.
Receive a random prize with a Crucible theme! It'll appear inside your MTX stash, waiting to be unwrapped.

Contains five Crucible Mystery Boxes, each containing a random prize with a Crucible Theme.

What's in the Crucible Mystery Box?
Thunderstruck Body Armour Variations
The Thunderstruck Body Armour leaves trails of lightning behind you, and periodically calls down lighting while you are idle. Rare and Unique enemies are struck by a powerful bolt when slain. There are also matching Boots, Gloves and a Helmet.
2 Variations: Thunderstruck Body Armour (3.48%), Scourgestruck Body Armour (1.49%)

Thunderstruck Body Armour

Scourgestruck Body Armour
Thunderstruck Helmet Variations
Replaces the appearance of a piece of headgear with the Thunderstruck Helmet.
2 Variations: Thunderstruck Helmet (3.48%), Scourgestruck Helmet (1.49%)

Thunderstruck Helmet

Scourgestruck Helmet
Thunderstruck Gloves Variations
Replaces the appearance of a pair of gloves with the Thunderstruck Gloves.
2 Variations: Thunderstruck Gloves (3.48%), Scourgestruck Gloves (1.49%)

Thunderstruck Gloves

Scourgestruck Gloves
Thunderstruck Boots Variations
Replaces the appearance of a pair of boots with the Thunderstruck Boots.
2 Variations: Thunderstruck Boots (3.48%), Scourgestruck Boots (1.49%)

Thunderstruck Boots

Scourgestruck Boots
Thunderstruck Cloak Variations
The Thunderstruck Cloak surges with electrical energy based on the number of skills you have used recently.
2 Variations: Thunderstruck Cloak (3.48%), Scourgestruck Cloak (1.49%)

Thunderstruck Cloak

Scourgestruck Cloak
Engineer's Body Armour Variations
Replaces the appearance of a piece of body armour with the Engineer's Body Armour.
2 Variations: Engineer's Bronze Body Armour (3.48%), Engineer's Cobalt Body Armour (1.49%)

Engineer's Bronze Body Armour

Engineer's Cobalt Body Armour
Engineer's Helmet Variations
Replaces the appearance of a piece of headgear with the Engineer's Helmet.
2 Variations: Engineer's Bronze Helmet (3.48%), Engineer's Cobalt Helmet (1.49%)

Engineer's Bronze Helmet

Engineer's Cobalt Helmet
Engineer's Gloves Variations
Replaces the appearance of a pair of gloves with the Engineer's Gloves.
2 Variations: Engineer's Bronze Gloves (3.48%), Engineer's Cobalt Gloves (1.49%)

Engineer's Bronze Gloves

Engineer's Cobalt Gloves
Engineer's Boots Variations
Replaces the appearance of a pair of boots with the Engineer's Boots.
2 Variations: Engineer's Bronze Boots (3.48%), Engineer's Cobalt Boots (1.49%)

Engineer's Bronze Boots

Engineer's Cobalt Boots
Engineer's Prototype Variations
Items you pick up are scanned by the Engineer's Prototype before they are sucked into your back pocket.
2 Variations: Engineer's Bronze Prototype (3.48%), Engineer's Cobalt Prototype (1.49%)

Engineer's Bronze Prototype

Engineer's Cobalt Prototype
Crystalarium Boots Variation
Changes the appearance of any equipped boots to the Crystalarium Boots. Crystals slowly encase you when you are stationary.
5 Variations: Topaz Crystalarium Boots (1.74%), Amethyst Crystalarium Boots (1.24%), Sapphire Crystalarium Boots (1%), Quartz Crystalarium Boots (0.75%), Ruby Crystalarium Boots (0.25%)

Topaz Crystalarium Boots

Amethyst Crystalarium Boots

Sapphire Crystalarium Boots

Quartz Crystalarium Boots

Ruby Crystalarium Boots
Suspicious Rock Pet Variations
The Suspicious Rock Pet is totally a rock and not at all an imp in a disguise. Rumours that this pet throws pebbles at others are unsubstantiated.
5 Variations: Suspicious Rock Pet (2.49%), Suspicious Sandstone Rock Pet (1%), Suspicious Sulphur Rock Pet (0.75%), Suspicious Azurite Rock Pet (0.5%), Suspicious Gold Rock Pet (0.25%)

Suspicious Rock Pet

Suspicious Sandstone Rock Pet

Suspicious Sulphur Rock Pet

Suspicious Azurite Rock Pet

Suspicious Gold Rock Pet
Planetary Orb Variations
The Planetary Orb Belt Attachment creates miniature planets which your Endurance, Frenzy and Power Charges orbit.
3 Variations: Planetary Orb (2.49%), Eldritch Planetary Orb (1.49%), Void Emperor Planetary Orb (1%)

Planetary Orb

Eldritch Planetary Orb

Void Emperor Planetary Orb
Ant Colony Pet Variations
The Ant Colony Pet summons a line of Ants that you can conduct. Summoning two of these pets causes your colony to grow even further.
3 Variations: Fire Ant Colony Pet (2.99%), Radioactive Ant Colony Pet (1.99%), Golden Ant Colony Pet (0.5%)

Fire Ant Colony Pet

Radioactive Ant Colony Pet

Golden Ant Colony Pet
Paladin Portal Variations
The Paladin Portal Effect calls forth a holy warrior who summons a portal from their sword as you approach. When their services are not required, they spend their time practising their swordplay.
3 Variations: Solar Paladin Portal Effect (2.49%), Lunar Paladin Portal Effect (1.49%), Crimson Paladin Portal Effect (1%)

Solar Paladin Portal Effect

Lunar Paladin Portal Effect

Crimson Paladin Portal Effect
Mage-Hunter's Aegis Variations
Increases to spell block chance form an arcane barrier over the Mage-Hunter's Aegis, which surges when you block a spell.
3 Variations: Mage-Hunter's Energy Aegis (2.74%), Mage-Hunter's Amber Aegis (1.49%), Mage-Hunter's Violet Aegis (0.75%)

Mage-Hunter's Energy Aegis

Mage-Hunter's Amber Aegis

Mage-Hunter's Violet Aegis
Coin Purse Variations
The Coin Purse Hip Attachment grants you the ability to flip a coin, for when you just can't decide.
4 Variations: Navali's Coin Purse (2.49%), Cadiro's Coin Purse (1.49%), Sin's Coin Purse (0.75%), High Templar's Coin Purse (0.25%)

Navali's Coin Purse

Cadiro's Coin Purse

Sin's Coin Purse

High Templar's Coin Purse
Botanist's Back Attachment Variations
With the Botanist's Back Attachment equipped, Endurance, Frenzy or Power Charges attach to a tree that just so happens to be growing out of your back.
3 Variations: Botanist's Enduring Back Attachment (2.49%), Botanist's Frenzied Back Attachment (1.49%), Botanist's Powerful Back Attachment (1%)

Botanist's Enduring Back Attachment

Botanist's Frenzied Back Attachment

Botanist's Powerful Back Attachment
Wildlife Aura Variations
The Wildlife Aura Effects replace the visuals of your Grace, Discipline or Determination Aura with serene animals.
3 Variations: Determined Wildlife Aura Effect (1.74%), Disciplined Wildlife Aura Effect (1.74%), Graceful Wildlife Aura Effect (1.49%)

Determined Wildlife Aura Effect

Disciplined Wildlife Aura Effect

Graceful Wildlife Aura Effect
Rare Finisher Effect Variations
The Finisher Effects amplify the deaths of Rare Monsters you kill.
5 Variations: Malachai's Demise Rare Finisher Effect (1.49%), Saqawal's Fate Rare Finisher Effect (1.49%), Kaom's Desire Rare Finisher Effect (1%), Purifier's Swordstorm Rare Finisher Effect (0.5%), Chayula's Grasp Rare Finisher Effect (0.5%)

Malachai's Demise Rare Finisher Effect

Saqawal's Fate Rare Finisher Effect

Kaom's Desire Rare Finisher Effect

Purifier's Swordstorm Rare Finisher Effect

Chayula's Grasp Rare Finisher Effect
Distribution
The chances of getting one of the distinct microtransaction types is 1/20. However, the chance of getting a specific thematic variation of those microtransactions varies and is listed above, next to each variation.
Note that these chances only apply to the first box you open. Every subsequent box you open increases your chances for the other microtransactions, due to the lack of duplicates.
How to open your Mystery Boxes
After purchasing your Crucible Mystery Box, you can find it in the Consumable section of your microtransaction stash in-game waiting to be unwrapped.
Note that these Mystery Boxes have random outcomes. Some items are rarer than others (as listed above). You are guaranteed to get an item that is worth at least what you paid for it (50 points) and it's statistically more likely that you'll receive something of higher value.
Receive a random prize with a Crucible theme! It'll appear inside your MTX stash, waiting to be unwrapped.

Contains five Crucible Mystery Boxes, each containing a random prize with a Crucible Theme.

Once you've received a reward from a mystery box, it's possible to purchase extra copies of it in the store for the same price as the mystery box. These microtransactions will be available outside of mystery boxes when they enter the store one month after the league ends.
Thanks for your Support
Many thanks to everyone who has purchased a Mystery Box at any point in time. They've become a huge driving force in our ability to continue to create frequent updates like Path of Exile: Crucible! Thank you so much for your continued support.