Locked chest

The locked chest was an April Fools block.

Obtaining
When introduced, this block was indestructible except for explosions, allowing it to drop.

Natural generation
Every chunk generated between April 1 and April 5, 2011 had a small chance of having a locked chest in it.

Usage


on the chest would bring up a screen, and clicking on the "Go to Store" button would forward you to the "Minecraft Store". It linked to https://minecraft.net/store/loot.jsp, but now the original page was removed and an error is shown. An archived version of this page can be found here. Various items were "sold" in the Minecraft Store (see below). Clicking on the proceed to checkout button triggered a screamer in which a Velociraptor from the movie Jurassic Park growled loudly and flew across the screen.

Entering items totaling over $10,000 into the cart caused a window pop-up asking if you are prone to seizures. Entering OK made the screen start flashing. When first released, there was no seizure warning label; Notch later implemented it to avoid lawsuits and posts on the forum.

On April 2 (the day following April Fools), the store had the addition of a multicolored banner which read "♥ April Fools'! ♥", accompanied by a MIDI instrumental of Rick Astley's 'Never Gonna Give You Up'. Tobias Möllstam stated that this was "the best script he's written to date."

The store page also used the font tf2build.ttf from Team Fortress 2 which is downloadable from here.

Items "sold"
Twelve "items" were "available":
 * Steve Co. supply crate key ($3)
 * Steve Co. supply crate key 5-pack ($18)
 * Miner's helmet ($21)
 * Name change ($99)
 * Creeper saddle ($42)
 * Secret griefer identity ($155)
 * Enlargement pill ($2)
 * Response from support ($494)
 * Three "coming soon" items (priced at $75, $7, and $1499)
 * Regular padlock ($8)
 * Used the same image as the "coming soon" items.

Light source
Locked chests emitted a light level of 15.

Fuel
Locked chests could be used as fuel, lasting 15 seconds (or 1.5 items).

Trivia

 * Locked chests are a reference to the Mann Co. Supply Crates from Team Fortress 2, where a key must be purchased for $2.49 in the in-game shop called Mann Co. Store in order to open the crate.
 * This may have been what Notch was talking about in his Twitter post about a "silly secret project".
 * Locked chests could generate in mid air or in the tops of trees.
 * Locked chests could be placed next to each other to form a 2 block long chest like normal chests do. These two chests are still however "locked".
 * The server console outputted "added a chest!" each time a chest was generated.
 * The 5-key pack is actually $3 more than 5 single keys.
 * The archived page is available in reduced functionality here.
 * Locked chests made lava particles when broken.
 * The locked chest's ID was named, and it is the longest named ID in Minecraft history.
 * The Bedrock Edition, Legacy Console Edition and Minecraft website each have their own "Minecraft Store". However, they are actual in-game stores used to get downloadable content, purchase Java Edition as well as Minecraft merchandise, and are completely unrelated to the April fool's joke.