Minecraft has three kinds of command block. Impulse runs once when it gets power, Chain runs right after the block that points into it, and Repeat runs every tick while it is powered. Each can also be Conditional or Unconditional, and Needs Redstone or Always Active.
Intermediate Java Bedrock
The three types
| Type | Color | What it does | Good for |
|---|---|---|---|
| Impulse | Orange | Runs once each time it is powered | Buttons, doors, one-time messages |
| Chain | Green | Runs after the block that points into it | Doing several commands in a fixed order |
| Repeat | Purple | Runs every tick (20 times a second) while powered | Pads, timers, detecting players |
Get any of them with /give @s command_block, /give @s chain_command_block or /give @s repeating_command_block.
Conditional or unconditional
An unconditional block always runs when its turn comes. A conditional block only runs if the command block directly behind it succeeded. The arrow on a conditional block looks different, and the condition is checked against the block the arrow points away from. Use it to build if-then steps, such as giving a reward only when a check passes.
Tip A command counts as successful when it changed something. A /give to a full inventory, or a /kill with no matching target, fails and stops the conditional block after it.
Needs Redstone or Always Active
Needs Redstone waits for a signal from a button, lever, plate or redstone dust. Always Active (called Auto on Java) runs without any signal. A Repeat block set to Always Active runs forever, so it is the usual base for pads and detectors. A Chain block needs Always Active to run on its own after the block before it.
Tick delay
On Bedrock every command block has a Delay in Ticks box. 20 ticks make one second, so a delay of 100 waits five seconds before the block runs. Java command blocks have no delay setting. To wait on Java, use repeaters or a scoreboard timer (see the scoreboard guide). Our game time converter turns seconds into ticks.
Building a chain
- Place an Impulse or Repeat block as the head of the chain and point it in the direction you want.
- Place a Chain block in front of it, facing away from the head.
- Set every Chain block to Always Active. Add more in a straight line, or turn them to change direction.
- Give the head its signal. All the blocks run in order in the same tick.
Common mistake The arrow of each Chain block decides where the chain goes next. If the arrow points back at a block that is already part of the chain, nothing after it runs. Check the arrows first when only part of a chain works.
7 command block builds to copy · Command block not working? · Execute command builder
FAQ
What is the difference between Impulse, Chain and Repeat?
Impulse runs once per signal, Chain runs after the block pointing into it, and Repeat runs every tick while powered.
What does Conditional mean on a command block?
It only runs if the command block behind it was successful. Unconditional blocks always run.
What is a tick in Minecraft?
One game tick is 1/20 of a second. There are 20 ticks per second, so 100 ticks is five seconds.
Why does my Chain command block not run?
It is usually set to Needs Redstone, its arrow points the wrong way, or the block before it did not run. Set it to Always Active and check the arrows.
Is there a delay on Java command blocks?
No. Delay in Ticks is a Bedrock setting. On Java use repeaters or a scoreboard timer.
Checked by the Game Respawned editorial team against the current Java and Bedrock versions. Spotted something out of date? Tell us.