Vaal Orb is the most "mysterious" Orb in the Path of Exile. When used on an item, Vaal Orb will corrupt it, giving unpredictable results and disabling the possibility of further enhancing or altering the Item via other Orbs. Since there are a lot of ways the item can be changed after using Vaal Orb, and it's impossible to predict the outcome, using Vaal Orbs on your equipment is a real gamble. Most players will use it as the finishing touch, to give their items a chance to gain an additional powerful property. Vaal Orb, like the majority of other Orbs in Path of Exile, can be looted from slain monsters on most levels. It has a slightly lower drop chance than Chaos Orb, but since you can't repeatedly use it on your equipment or other consumables, they are pretty much of an equal value. Vaal Orb can be also obtained via the Vaal Orb Recipe, which requires you to vendor 7 Vaal Skill Gems and a random Vaal Sacrifice Fragment. It, however, doesn't seem like a trade to thrive for and can be ignored.

As mentioned, if you buy Vaal Orb and use it on a piece of equipment, it can have a number of different results depending on the item you use it on. Below you can see all the possible effects on the items Vaal Orb can be used on with a brief description. The potential, most profitable results have also been listed. When it comes to general equipment, Vaal Orb can:

1. Change nothing - it will simply Corrupt the item without altering any of the stats. The item will only gain the "Corrupted" attribute which makes you unable to use other Orbs on it;
2. Change socket colors to white - with approximately 25% chance for a socket to change its' color, and an additional 10% for each consecutive socket to change as well. It sums up to about 0,00025% chance for all six sockets to turn white on an Item;
3. Reroll the item into a rare with a new random number of sockets and links - this most likely means you have just completely ruined ("bricked", in slang used by gamers) your item and you can vendor it straight away, this has a similar effect to Chaos Orb with a very high chance of giving you completely useless composition of Sockets and links on the item;
4. Add a unique Vaal Implicit modifier - this will remove the actual Implicit modifiers on the item if there are any, but this is usually the best thing that can happen when using a Vaal Orb. Using Vaal Orbs on majority of Items can give them very powerful Vaal properties which includes giving you the chance to Curse enemies with every Hit on Gloves, increase the number of Maximum Frenzy Charges (Belt), Power Charges (Helmet) and Endurance Charges (Boots) or give you a +1 Chain or +1 Arrow on Quivers (the Quiver Mods can be worth a fortune if you get them on a solid base);
5. Transform certain Unique Items into another Unique - for example, Malachai's Vision and Blood of Corruption are obtainable only via Corrupting Voll's Vision and Tear of Purity.

Players can also corrupt Maps which is quite common since it can't render the item useless, but will always grant them additional effects. Even if Vaal Orb doesn't change any of the properties on a Map, all Corrupted Map Bosses have a chance to drop Vaal Fragment when slain. When it comes to Maps, Vaal Orb can:

1. Change nothing - except for corrupting the Map;
2. Reroll the Map with random affixes - with a chance to increase the Map Tier by 1 level. Hence, Tier 15 Map which is corrupted this way, has approximately 50% Chance to turn into a Tier 16 Corrupted Vaal Temple Map;
3. Reroll the Map and give it exactly eight affixes - item corrupted this way always retains its' base, and has always eight new affixes;
4. Unidentified the item - retaining the Map's base, and Item Quantity and Rarity bonuses.

Corrupting Gems is also possible in Path of Exile, which is the best way to obtain their corresponding Vaal Gems, and it's one of the ways to upgrade your Gems above their maximum level and Quality percentage to above 20. When using a Vaal Orb on a Skill or Support Gem the possible outcomes are:

1. Nothing changes - the Gem, however, gets Corrupted and you can no longer alter it's Quality or the level above 20;
2. Gem's level increases or decreases by 1 - Gems can be upgraded above their maximum level, up to level 21 this way. Gems that have their level reduced can be leveled up again to 20;
3. Gem's quality increases or decreases by 1-10 - Gems can reach up to 23% Quality that way. If your Gems lose Quality in the process, you will no longer be able to upgrade it by any mean;
4. Gem turns into a corresponding Vaal Gem - retaining its level and Quality. If you are aiming to get this effect, make sure to Upgrade the Quality beforehand;

The last group of items that can be altered using Vaal Orbs is Jewels. Since Jewels do not initially carry any Implicit modifiers, it's a great way to slightly upgrade them. However, as usual, it's not the only possible outcome. If you use Vaal Orb on a jewel these are the potential results:

1. Nothing changes - similar to all other items, you simply get the "Corrupted" attribute and you no longer can change this Jewel;
2. Vaal Implicit modifier gets added - which is usually the best possible outcome, and modifiers like Immunity to Corrupted Blood, increased Damage, or Crit. Chance are the ones you should count on getting;
3. Jewel turns into a random rare or Vaal-exclusive Unique Jewel - which is one of the few ways to obtain some Vaal Unique Jewels like for example Fevered Mind, which is one of the most popular ones from the available options.

Players can even use Vaal Orbs to corrupt Strongboxes. As a result, some of the items in the Strongbox will drop Corrupted and at the same time, identified. Flasks, Currencies, Essences, Fossils, Resonators, Fragments, and Quest Items cannot be corrupted using a Vaal Orb.

While Vaal Orbs can multiply the value of items you Corrupt, it makes any player unable to change it further by any mean. It cannot be modified in any way, except for changing the sockets via Crafting Bench. This means you should be fully aware of the possible outcome and accept the risk. After all, using Vaal Orb is a complete gamble. You can buy Vaal Orbs from other players with the use of real cash on the Odealo market. On Odealo you can find Vaal Orbs for sale on all the platforms available including PC, Xbox One, and PS4. Since you can buy it directly from other players, you can expect the lowest prices and with fast delivery times. Buying Vaal Orbs from regular players with real money is also the most secure way to participate in this type of trades.