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“A command block is a block that can execute commands. Because it cannot be obtained or edited in Survival mode without cheats, it is primarily used on multiplayer servers, in Creative worlds, and custom maps.” — Minecraft Wiki, The King
Execution: The command block can execute any command in Minecraft so long as it is typed. If the command block is put into a powerful enough staff, it can execute multiple commands at once instantly, with no need to type. Notable abilities with commands include:
Building and Destruction: Through the /setblock or /fill commands, it can build with any block in Minecraft and destroy through setting blocks to air.
Item Granting: Through the /give command, it can give any item in Minecraft to entities infinitely.
Summoning: It can summon any entity in Minecraft through the /summon command.
Teleportation: By using /tp or /teleport, it can teleport users anywhere in the area.
Effect Granting: It can grant any effect in Minecraft through the /effect command. There is seemingly no way to be immune to this, as King Orange is able to give Purple negative effects despite the latter having the Minecraft Game Icon combined.
Entity Modification: Through the /data command, it is possible to modify various things about an entity, including things the base game does not include. Yellow does this in The Raid, using the command "data modify entity @s light_level set value 15", which adds a light source, though only to the command block staff instead of himself.
Structure Saving/Loading: Through the /structure command, it's possible to save and load structures. It's used in The Raid to save and load the ravager model, as well as to create a barrier shield during the nether section. This is the only Bedrock Edition exclusive command to be used in AVM.
Shielding: Through setting the value of the attribute "generic.shield_size", it can generate white, transparent bubble-shields around entities, protecting them from projectiles while seemingly allowing other entities to pass through, as seen in The King. The Minecraft Game Icon is also capable of this, but this requires a staff.
Countdown: Counted down through "function minecart_race".
Malfunction: The command block can malfunction if it gets struck by lightning, which causes it to quickly flip between all possible command block textures, execute random commands by itself, and make nearby command blocks also malfunction. If an already malfunctioning command block is struck by lightning, the background will convert to random blocks as well as beginning to slowly rotate, gravity will cease, and living creatures will be pixelated before slowly being converted into blocks.