Nether Reactor

The nether reactor was a player-built structure exclusive to which, when activated in Survival mode, a massive structure of netherrack, the nether spire, spawned large quantities of normally rare or unobtainable items.
==Creation==
The reactor was constructed by placing gold blocks, cobblestone and a nether reactor core in the 3×3×3 arrangement. Air blocks were required on the middle and top layers. If the structure was incorrect, attempting to activate the reactor resulted in the client message "Not the correct pattern!". The messages were also sent to players on Creative mode.
===Activation messages===
Messages 	Description
Client message: Active! 	Activated successfully.
Client message: Not the correct pattern! 	Cannot activate due to an incorrect structure pattern.
Client message: All players need to be close to the reactor. 	All players must be close to the reactor to be activated.
Client message: The nether reactor needs to be built lower down.	Nether spire cannot be created because the location of the nether reactor is too high.
==Behavior==
To activate a nether reactor, the following conditions needed to be met:
*All players were in the range of the reactor's effects on activation.
*The reactor was built within the valid range (between the Y layers 4 to 96).
*The player who activated the reactor was standing level with the structure.
If those conditions were met, tapping the core would activate the reactor, sending the client message "Active!". Immediately after activation, a massive structure of netherrack with multiple rooms, the nether spire, was generated around the reactor. The bottom room, which contains the reactor, replaced all blocks other than those of the reactor with air, while blocks in the upper levels remained intact. The spire was composed of over 25 stacks worth of netherrack. 
Items would begin to spawn within the reactor room, including glowstone dust, nether quartz, cacti, sugar canes, both types of mushrooms, bows, bowls, books, oak wooden doors, beds, pumpkin seeds and melon seeds. Zombified piglins were also able to spawn. During this stage, the blocks that made up the reactor were converted into glowing obsidian and the core adopted a red texture to symbolize the activation. Excluding the core, any part of the reactor could be mined after activation and it would still function. This way, the player could recycle the expensive gold blocks. It was possible to recover all 4 blocks provided the player worked quickly. All aspects of the reaction froze when the player mined the active core: if the nether reactor core was mined out while the nether reactor is active, the glowing obsidian would not turn into obsidian after the reactor deactivates. This also caused the reactor to stop spawning items and zombified piglins, and make the day/night cycle freeze at nighttime for several in-game days.
The reactor cycle would end after 45 seconds, damaging the reactor's structure and changing the world to night. Because the spire could not replace blocks past the world border, when the reactor was activated near the edge of old worlds the player would be able to see the time set to night. The reactor was replaced with a 3×3×3 box of obsidian containing the core, which adopted a dark blue texture to indicate that the reaction has ended. If the player built a new reactor around the burnt-out core, the netherrack spire would generate, although the rest of the reaction would not take place.
==History==
Pocket Edition v0.5.0 alpha Development nether reactor.png| A nether reactor in 0.5.0.
Completed Nether Reactor.png|A nether reactor ready to be activated.
Nether Reactor Activation.png|A nether reactor after activation in 0.5.0, with the gold blocks still retrievable.
Reactor.jpg|An active nether reactor spawning items and zombie pigmen.
Spent Reactor.jpg|A nether reactor upon completion of the cycle.
Nether Reactor.png|Nether Reactor
Progress 1 Nether Reactor.png|Progress 1 nether reactor
Progress 2 Nether Reactor.png|Progress 2 nether reactor
Progress 3 Nether Reactor.png|Progress 3 nether reactor
Progress 4 Nether Reactor.png|Progress 4 nether reactor
Progress 5 Nether Reactor.png|Progress 5 nether reactor
Progress 6 Nether Reactor.png|Progress 6 nether reactor
Finished Nether Reactor.png|A finished nether reactor
Category:Player-built structures
de:Netherreaktor
es:Infrarreactor
fr:Réacteur du Nether
ja:ネザーリアクター
pl:Reaktor Netheru
pt:Reator do Nether
ru:Реактор Нижнего мира
uk:Реактор Нижнього світу
zh:下界反应器