Block of the Week: Command Block

The list of blocks left to cover in our Block of the Week series is getting shorter and shorter, and we’ve almost reached the end. So this week, we wanted to cover a block that we know a lot of you have been waiting for us to feature for a very long time. It’s the command block, of course! What else were you expecting?

Command blocks, as you might expect from the name, execute commands. What kind of commands? Well, almost anything you can imagine - from spawning objects, to teleporting players, to awarding advancements, to changing gamemode, to status effects, to changing the world, to modifying inventory, to a zillion more things. There’s a great list on the Minecraft wiki.

If you mostly play survival mode, and you’re thinking “that sounds a lot like cheating”, then you’re right - which is why command blocks aren’t available in survival mode. They’re a feature that we built specifically for creative mode, and for adventure mode mapmakers. Jeb announced their existence in a tweet in July 2012, and they were added to the game in version 1.4.2 - the Pretty Scary Update, which also added spooky anvils, creepy flowerpots and terrifying carrots on sticks.

Ever since version 1.9 of Minecraft, there have actually been three kinds of command block, which you can switch between with a button in the interface. The impulse one is orange, and executes once every time it’s activated. The chain command block is green and executes when a command block pointing to it is executed. Finally, the repeating command block is purple, and executes a command once per game tick when activated.

There are a couple of other options in the command block interface too - conditional command blocks will only execute if the command block physically behind it successfully executes its own command, while unconditional ones will always execute their commands when triggered. You can also set command blocks to require a redstone pulse to activate or remain always active.

With combinations and chains of configured command blocks, you’ll find it’s possible to do just about anything you can imagine. You can create lotteries, item trade systems, passwords, teleporters, prisons, clickable words, weather machines, obstacle courses and even houses that are bigger on the inside than the outside. A proper tutorial is more than we can manage here, but there are loads of good ones easy to find online already.

You might be reading this and thinking “this all sounds very complicated”, and to be honest you’d be right. Command blocks are definitely more of an advanced feature. But there’s good news. In the upcoming Update Aquatic, we’re revamping the whole command system to make it much better and easier to use. That should let everyone dip their toes into what we think is one of the best bits of the game!