Java Edition:Air Trade
Throughout many snapshots of Minecraft, it has been possible to create villagers with trades containing air. These trades are unusable as no air item exists.
Dangers
In 1.10.2 and below, villagers that have trades with air as either the buy or sell item (not the buy2 item) will savestate the chunk they are in. Moving these villagers becomes impossible after they are first written to disk, as they will savestate any chunk they are in instantly and vanish upon reloading if moved to a different chunk.
Attempting to hover over a buy or sell item that is air or placing emeralds into the buy slots with a trade selling air taking priority will also crash the game.
These dangers are fixed in 16w32a (a 1.11 snapshot), which introduced the usage of a static "empty" ItemStack instance instead of using null.
Obtaining Air Buy Trades
Downgrading Sweet Berries
Sweet berries were added in 18w49a (1.14 Snapshot), and butcher villagers could buy sweet berries as a master level trade starting in 19w11a (1.14 Snapshot). You can use downgrading to get air trade from a butcher villager. First, you must have a butcher villager with the sweet berry buy trade. Then, downgrade to before 18w49a. This converts the sweet berries to air, giving the villager an air buy trade. Due to the nature of this downgrade, the butcher will lose its profession and career. It will change into a farmer, fisherman, shepherd, or fletcher.
Obtaining Air Sell Trades
Broken Cake Trade
In 14w02a (a 1.8 snapshot), farmer villagers were supposed to sell cake at tier 4. However, due to a bug[1] farmer villagers will instead sell the Cake (Block Item) for 1 emerald. As the cake block does not have a registered item in 13w37a (a 1.7 snapshot) and above, opening this villager's GUI before reloading from disk after unlocking its tier 4 trades will crash the game whilst trying to write the villager's trades to the trade packet. When the villager is saved to disk, 0 is written as the item id, converting it to air.
Downgrading Campfire
Campfires were added in 19w02a (1.14 Snapshot), and fishermen villagers were able to sell campfires starting in 19w11a (1.14 Snapshot) as an apprentice tier trade. After obtaining a fisherman villager with this trade, you must downgrade to before 19w02a. This converts the campfires to air, giving the villager an air sell trade.
Downgrading Leather Horse Armor
Leather horse armor was added in 19w08a (1.14 Snapshot), and leatherworker villagers could sell leather horse armor as an expert tier trade starting in 19w11a (1.14 Snapshot). After obtaining a leatherworker villager with this trade, you must downgrade to before 19w02a. This converts the leather horse armor to air, giving the villager an air sell trade.
Downgrading Globe Banner Pattern
Globe banner patterns were added in. 19w11a (1.14 Snapshot), and cartographer villagers could sell the globe banner pattern starting in the same version. After obtaining a cartographer villager with this trade, you must downgrade to before 19w02a. This converts the globe banner armor to air, giving the villager an air sell trade.
Downgrading Small Dripleaf
Downgrading Dripstone Block & Pointed Dripstone
Downgrading Moss Block & Rooted Dirt
Obtaining Air Buy or Air Sell Trade
23w13a_or_b Votes
The April Fools' snapshot 23w13a_or_b introduced several methods to obtain normally unobtainable features, including downgradeable items .
- The
villager_gemvote, when applied, will replace all emeralds in new villager trades with any item (without NBT), this includes downgradeable items .
The villager_gem vote will replace all emeralds of a villagers new trade with any item (without NBT). This will not replace any current gem trades, including emeralds or items that were applied through this vote. If this vote is removed or altered, any new trades that any previous villagers receive will return to using emeralds, or be replaced by the new item. Villagers affected by this vote will retain their trades upon downgrading or updating, if the item does not exist within that version it will become air, otherwise the item will be preserved.
Obtaining Air for Air Trades
Item Stack Component
In 24w09a (1.20.5 Snapshot), the NBT data system was overhauled into the Component system. Downgrading a villager with any trades from 24w09a to 24w07a (1.20.5 Snapshot) or before will convert the items into air, giving the villager trades which sells air but uses air as payment.
22w13oneBlockAtATime Villagers
In the April Fools' version 22w13oneBlockAtATime, villagers did not have a trading GUI. Downgrading or upgrading a villager into 22w13oneBlockAtATime will remove the villagers trading GUI, updating the villager out of 22w13oneBlockAtATime will convert the items into air, giving the villager trades which sell air but uses air as payment.
Gallery
A villager selling air but with a payment of air.
A villager buying and selling a wide range of items.
See also
References
Work in Progress
This page is not quite complete and is missing information, below is a list of everything that needs completed on this page.
- The "Pre-Downgrade Range 1" end version is currently unknown.
- The "Post-Downgrade Range 1" start version, 18w48a (1.14 Snapshot) needs testing.
- The "Pre--Downgrade Range 2" end version is currently unknown.
- The "Post-Downgrade Range 2" start version is currently unknown.
- The "Pre-Downgrade Range 3" end version is currently unknown.
- The "Post-Downgrade Range 3" start version, 20w46a (1.17 Snapshot) needs testing.
- The "Post-Downgrade Range 4" start version is currently unknown.