The Challenge:

Design a redstone circuit that accepts an input from a button and lights up a random redstone torch.

The Rules:

  • One redstone torch should be lit, with all the others off.
  • The state of the torches should be held indefinitely until the button is pressed again
  • The circuit must be stable (it can't burn out).
  • There should be at least 2 torches.


enter image description here

Answers will be judged based on the amount of redstone used. Please submit answers in the form of an image, created using Baezon's Redstone Simulator.

  • For discussion on this kind of question, see here.
    – Kevin Yap
    Jan 29, 2011 at 23:04
  • 1
    Hm. Interesting prospect. While I have no knowledge of redstone circuitry, I'd imagine you'd have to construct a looping current that passes through a couple of AND gates. Press the button, and then signal can pass through the next AND gate to light up a random torch. Here's a question for you, though: Should the design be repeatable, or do you expect solutions to need resetting in between random-torches. Jan 29, 2011 at 23:15
  • I suppose either. Perhaps there would be a repeatable solution and an automatically resetting solution. I'll have to see how well this turns out, though.
    – Kevin Yap
    Jan 29, 2011 at 23:21
  • Does the circuit as a whole need to be stable (work all the time) or does the entire thing need to be slow?
    – Nick T
    Jan 30, 2011 at 19:57
  • 1
    Redstone golf has been ruled as off-topic as per this answer.
    – Kevin Yap
    Jan 30, 2011 at 23:06

1 Answer 1


I really enjoy messing around with redstone, so here is my go at my own challenge: (if anybody else has a solution, feel free to also post it - I just posted this to get the ball rolling)

71 Redstone Wire, 15 Redstone Torches

The previous two solutions had a slight glitch with the clocks that caused the chance of the left torch lighting up to be 5/8 rather than 1/2. This new solution uses a 4-clock, ensuring the chances are equal.

enter image description here

53 Redstone Wire, 17 Redstone Torches

Did some rearranging and managed to shave off a massive 5 redstone.

enter image description here

58 Redstone Wire, 17 Redstone Torches

enter image description here

The user presses the button located at the bottom of the schematic, and travels along the two wires squared in green. (The wire goes all the way under the yellow blocks, but the schematic doesn't quite show it.) When these wires are powered, the bottom input of the AND gates are also powered (squared in brown).

The area squared in red is a clock generator (a device that constantly cycles). A wire comes off of the generator, and travels to the top inputs of the AND gates. The inverter (or NOT gate), squared in purple, ensures that the wires coming off of the clock are always opposite.

When the user presses the button, the lower torch on the AND gates turn off, causing the output of the gates to alternate on and off. The outputs are hooked up to the R and S inputs of the RS-NOR latch, squared in blue. An RS-NOR latch can be thought of as a one bit memory cell. The input that last received a signal will stay off until the other input receives a signal.

Because the RS-NOR latch is effectively hooked up to the clock, it will cycle for a second (due to the button press) an eventually stop on either an off or on position.

The output of the RS-NOR is wired to both of the torches - one path going through an inverter (orange) so both torches always display something different.

Here is what is looks like in game:

enter image description here

  • 1
    Note that if you test this out in the simulator, the RS-NOR latch may occasionally start to flicker until you press the button again. This is because the simulator is very similar to (but not an exact replica of) the actual mechanics of redstone in-game.
    – Kevin Yap
    Jan 30, 2011 at 7:56
  • 3
    huh???????????? Jan 31, 2011 at 5:34

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