OR gate in redstone

Two dust lines walking toward each other, merging into one. The simplest gate in redstone. Footprint 3 wide × 3 deep × 1 tall. Build it block by block in Minecraft.

How to build it

The photo shows two levers facing each other with their dust meeting in the middle:

1. Place your two input levers, one on each side, spaced a couple of blocks apart.
2. Run redstone dust from each lever toward the gap between them.
3. The two dust lines touch and merge. From that merge point, run dust upward (or outward) to wherever you want the output.

In the picture, the dust merges and continues straight up to a note block. One continuous line, no blocks or torches needed.

Why it works

Redstone dust connects to any other dust in a cardinal direction and carries whatever power reaches it — taking the strongest source. A merged line reads as "on" whenever either input lever is on, which is exactly the truth table for OR.

Why no blocks?

OR is the one gate that doesn't need any inversion. AND and NAND need torches; XOR needs several. OR is just "wires that touch". That makes it the cheapest gate to build in redstone and the most compact.

Gotchas

• Dust loses one strength per block. If your merged line runs far, add a repeater somewhere along it to refresh back up to 15.
• Dust takes the strongest input, it doesn't sum. If one lever is already on, flipping the second doesn't make the output "brighter" — it just stays on.