Minecraft is basically a game about building, sure, but eventually, everyone gets the itch to destroy something. Maybe it’s a mountain blocking your view. Maybe your friend built a dirt shack way too close to your mega-base. Whatever the reason, learning how to create a cannon in minecraft is a rite of passage. It's that moment where you stop being a builder and start being an engineer. Honestly, the first time I tried this, I ended up with a massive crater where my house used to be because I forgot one single bucket of water. Don't be like me.
Redstone is finicky. It’s essentially the electrical wiring of the Minecraft world, and when you combine it with TNT, things get volatile fast. You aren’t just placing blocks; you’re managing timing, physics, and explosion vectors. If your timing is off by a fraction of a second, the TNT meant for your "bullet" explodes inside the barrel. Boom. Back to the respawn screen.
The Physics of TNT Launching
Before we start placing blocks, you have to understand the "why" behind the build. TNT in Minecraft has two distinct phases. When you ignite it, it becomes a "primed" TNT entity. It loses its collision box, falls through other entities, and—this is the important part—it can be moved by other explosions.
To make a cannon, you’re basically creating a combustion chamber. You have one set of TNT charges (the propellant) and one single TNT block (the projectile). The goal is to have the propellant explode just as the projectile’s fuse is about to run out. If you time it right, the force of the first explosion kicks the second one across the map. If you do it wrong? You’ve just made a very expensive self-destruct button.
Water is your best friend here. In Minecraft, explosions do zero damage to blocks if the explosion happens inside a water source block. However, that explosion still exerts "knockback" force on other entities. So, by submerging your propellant in a shallow stream of water, you protect your cannon’s structure while still getting all the power needed to launch your shot.
Building Your First Classic TNT Cannon
Let's get into the actual build. You'll need some solid blocks—obsidian or cobblestone are the favorites because they can handle a mistake or two—along with some redstone dust, a few repeaters, a button, and buckets of water.
Start by laying out a U-shape. Usually, a 3x8 or 3x10 frame works best.
Put a source block of water at the very back of the "U." The water should flow toward the open end. If it goes too far, you’ve made it too short. If it stops early, your barrel is too long. At the very end of the water stream, place a stone slab. This slab is crucial. It holds the projectile TNT slightly higher than the propellant, which helps the physics engine calculate a forward trajectory rather than just blowing it straight up into the air.
Now for the wiring. This is where people usually mess up. You need two separate lines of redstone.
One line goes directly to the propellant TNT. This one should be instant. The second line goes to the projectile at the end of the barrel. This line must have redstone repeaters. I usually suggest at least four repeaters set to the maximum delay (four ticks each). This creates that necessary window of time for the propellant to "prime" before the projectile is even ignited.
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Basically, you press the button, the propellant hiss starts, you wait a beat, the projectile ignites, and then—thwack—the first explosion sends the second one flying.
Why Your Cannon Keeps Exploding
I see it all the time on servers. Someone builds a massive obsidian tube, fills it with fifty blocks of TNT, and then wonders why their base is gone.
The most common mistake is "clogging." If you place a TNT block over your water source, the water disappears. Without the water, the propellant destroys the cannon. Always leave that back source block open.
Another issue is timing. If your projectile ignites too early, it will explode while it's still sitting on the slab, which often causes a chain reaction back into the propellant. If it ignites too late, it might fly, but it’ll explode mid-air before hitting the target. Adjusting your repeaters is like sighting in a rifle. It takes practice.
Modern Variations: The Dispenser Method
If you're playing on a modern version like 1.20 or 1.21, the old manual way is kinda slow. Who wants to keep placing TNT by hand?
Enter the Dispenser.
By using dispensers to drop the TNT into the water, you can create a semi-automatic weapon. You can stack these dispensers on top of each other. Imagine three rows of five dispensers all triggering at once. That's fifteen blocks of TNT propellant. The distance you can get with that kind of power is honestly ridiculous. You can launch a projectile so far that it unloads the chunks it's traveling through, which can sometimes lead to "ghost" explosions or the TNT simply vanishing if the server can't keep up.
Advanced Tactics: Long-Range and Spread Shots
Once you’ve mastered the basic how to create a cannon in minecraft logic, you can start getting fancy.
The Sand Cannon: If you want to actually breach a wall on a faction server, launching TNT isn't enough. TNT that explodes against a wall won't break the blocks if there's water protecting the wall (a common defense). However, if you launch a block of sand and a block of TNT simultaneously so they land at the exact same time, the sand "glitches" into the same space as the TNT. This allows the TNT to explode inside the sand, bypass the water protection, and blow a hole in the base. It’s a bit of an exploit, but it’s been a staple of Minecraft warfare for a decade.
The Shotgun: Instead of one projectile, place a whole row of slabs at the end. When the propellant goes off, it launches five or six TNT blocks at once. It’s not accurate. It’s messy. But it’s incredibly effective for clearing out a forest or a large build quickly.
Directional Aiming: By slightly offsetting the propellant (placing more on one side of the water stream than the other), you can actually "arc" your shot. It’s hard to master because Minecraft’s hitboxes are square, but it’s possible to steer your shot left or right.
Safety Measures and Troubleshooting
Let's talk about the "Obsidian Rule." If you can afford it, build the entire cannon out of obsidian.
Yes, it's a pain to mine. Yes, it looks a bit edgy. But if you make a mistake in your redstone timing—and you will—obsidian won't break. If you build your cannon out of cobblestone and it fails, you have to rebuild the whole thing. If an obsidian cannon fails, you just dry it off and try again.
Check your server lag. If you’re playing on a high-latency server, redstone can skip ticks. This is the silent killer of Minecraft cannons. If the server skips the tick where your water is supposed to protect your blocks, the cannon is toast. On laggy servers, I usually add an extra repeater to the projectile line just to be safe.
Also, watch out for "Entity Cramming." In newer versions of the game, if too many entities (like primed TNT) are in one small space, they start pushing each other out or even despawning. Keep your propellant amounts reasonable. More isn't always better; sometimes more just means your projectile gets launched into the stratosphere where it does absolutely nothing.
Moving Forward With Your Build
Building a cannon is the first step toward understanding the more complex side of Minecraft. It teaches you about entity physics, redstone timing, and the importance of fluid dynamics. Once you have a working model, don't just stop there.
Try to automate it. Connect it to a clock circuit so it fires every five seconds. Try to shrink it down. There are designs for "pocket cannons" that are only 3x3x3 blocks but can still toss a TNT block fifty meters.
The best way to learn is through failure. Go into a creative world, give yourself a stack of TNT and a button, and start experimenting. See how many repeaters it takes to get the perfect arc. See what happens when you use a fence post instead of a slab at the end of the barrel. Minecraft is a sandbox, and sometimes that sand needs to be launched at a high velocity.
To take this to the next level, start looking into TNT Duplicators. While technically an exploit, they are widely used in the technical Minecraft community (like the Scicraft or Hermitcraft players) to create "world eaters" that can clear out thousands of blocks automatically. It uses slime blocks and coral fans to trick the game into primed TNT without consuming the block. It’s the peak of cannon technology, but it’s a steep learning curve.
For now, stick to the basics. Get your water flowing, get your repeaters timed, and watch the sparks fly. Just remember to stay clear of the blast radius. Even with armor, a point-blank TNT blast is rarely a fun time.