Image from official site catan.com

How Provably Loaded Dice Lead To Unprovable Cheating

Here’s a really interesting writeup by [Mike] that has two parts. He shows that not only is it possible to load wooden dice by placing them in a dish of water, but that when using these dice to get an unfair advantage in Settlers of Catan, observation of dice rolls within the game is insufficient to prove that the cheating is taking place.

[Mike] first proves that his pair of loaded dice do indeed result in a higher chance of totals above seven being rolled. He then shows how this knowledge can be exploited by a Settlers of Catan player to gain an average 5-15 additional resource cards in a typical game by taking actions that target the skewed distribution of the loaded dice.

The second part highlights shortcomings and common misunderstandings in current statistical analysis. While it’s possible to prove that the loaded dice do have a skewed distribution by rolling them an arbitrary number of times, as [Mike] and his wife do, it is not possible to detect this cheating in a game. How’s that? There are simply not enough die rolls in a game of Settlers to provide enough significant data to prove that dice distribution is skewed.

Our staff of statistics Ph.D.s would claim that [Mike] overstates his claims about shorcomings in the classical hypothesis testing framework, but the point remains that it’s possible to pass through any given statistical testing process by making the effect just small enough. And we still think it’s neat that he can cheat at Settlers by soaking wooden dice in water overnight.

This isn’t the first time we’ve seen Settlers of Catan at the center of some creative work. There’s this deluxe, hand-crafted reboot, and don’t forget the electroshock-enabled version.

[via Reddit; images from official Catan site]

Spice Up Your Dice With Bluetooth

There’s no shortage of projects that replace your regular board game dice with an electronic version of them, bringing digital features into the real world. [Jean] however goes the other way around and brings the real world into the digital one with his Bluetooth equipped electronic dice.

These dice are built around a Simblee module that houses the Bluetooth LE stack and antenna along with an ARM Cortex-M0 on a single chip. Adding an accelerometer for side detection and a bunch of LEDs to indicate the detected side, [Jean] put it all on a flex PCB wrapped around the battery, and into a 3D printed case that is just slightly bigger than your standard die.

While they’ll work as simple LED lighted replacement for your regular dice as-is, their biggest value is obviously the added Bluetooth functionality. In his project introduction video placed after the break, [Jean] shows a proof-of-concept game of Yahtzee displaying the thrown dice values on his mobile phone. Taking it further, he also demonstrates scenarios to map special purposes and custom behavior to selected dice and talks about his additional ideas for the future.

After seeing the inside of the die, it seems evident that getting a Bluetooth powered D20 will unfortunately remain a dream for another while — unless, of course, you take this giant one as inspiration for the dimensions.

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ROBOCHOP! It Slices, Dices, But Wait! There’s More…

You’re gunna love my cuts. 

KUKA robots are cool. They’re both elegant and terrifying to watch in action as they move unyieldingly to preform tasks. Not many of us get to use industrial tools like this because they aren’t exactly trivial to wield (or cheap!). Artists [Clemens Weisshaar] and [Reed Kram] however created an installation that allows anyone to potentially control one of these orange beauties to do their bidding… all from the safety and comfort of a computer chair.

For their piece, “ROBOCHOP”, the artists developed a web app that allows you to easily manipulate the surface of a virtual cube. You can rotate for positioning and then use a straight or curved line tool to draw vectors through its surface and subtract material. Once you’re finished sculpting your desired masterpiece, one of the four KUKA robots in the installation will retrieve a 40 x 40 x 40 cm block of foam and shape it into a real-life version of whatever you created in the app.

Screen Shot 2015-03-06 at 1.03.39 PMStarting today you can visit the project’s website and upload your own mutilated cube designs. If your design is selected by the artists, it will be among the 2000 pieces carved by the robots throughout their installation during CeBit in Hanover. After the show, your cube spawn will then be mailed to you free of charge! The only way I could see this being cooler, is if they filmed the process so you could watch your shape being born.

Anyhow, I personally couldn’t resist the invitation to sculpt Styrofoam remotely with an industrial grade robot arm and came up with this gem.

You can go to their page if you want to give the app a go, and really… why wouldn’t you?

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ChipKIT Powered Electronic Dice

Electronic Dice Replaces Human Influence

[Will] likes his board games but can’t seem to keep from loosing the dice. He’s been using a dice-rolling smartphone app for a while now and decided that it was time to make a dedicated microcontroller dice roller.

The brain behind the dice roller is a chipKIT uC32 microcontroller. Seven output pins are connected to 7 appropriately-arragned LEDs in the top of the dice. There is only one more electrical component, a momentary switch, that is used to re-roll. When the button is pushed, a random number between 1 and 6 is generated and then displayed via the LEDs in true dice fashion. [Will] wrote his own code for this project and makes it available for anyone to download. The case is 3D printed and was designed in Tinkercad, the files of which are also available. The chipKIT is attached to the 3D printed base by a pair of zUNO clips. Find a short video of this thing in action after the break….

Digging the randomness of the roll but miss the realness of the dice? Check out this real dice roller. Need two electronic dice? Check these.

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Roll With Dicebot, The Tweeting Dice Roller

dicebot

[David] modernized a 1920’s dice rolling game to bring us DiceBot, a twitter enabled dice rolling robot. DiceBot started with an antique dice tin. The original tin was human controlled. Pushing a button on the side of the tin would spin the bottom, rolling the dice.

It’s a bit hard to push a button from across the world, so [David] added a small motor to spin the tin. He connected the motor to a simple L298 motor driver chip, and wired that up to a Raspberry Pi. The Pi runs a few custom Ruby scripts which get it on the internet and connect to the Twitter API.

Operation is pretty straightforward. A tweet to @IntrideaDiceBot with the hashtag #RollTheDice will cause the Dicebot to spin up the dice. Once things have settled, DiceBot captures an image with its Raspberry Pi camera. The dice values are checked using OpenCV. The results are then tweeted back, and displayed on DiceBot’s results page.

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The Most Random Electronic Dice Yet

di

If you’ve written a great library to generate random numbers with a microcontroller, what’s the first thing you would do? Build an electronic pair of dice, of course.

[Walter] created the entropy library for AVRs for a reliable source of true random numbers. It works by using the watchdog timer’s natural jitter; not fast by any means but most sources of entropy aren’t that fast anyway. By sampling a whole lot of AVR chips and doing a few statistical tests, it turns out this library is actually a pretty good source of randomness, at least as good as a pair of dice.

The circuit itself uses two 8×8 LED matrices from Adafruit, an Arduino, and a pair of buttons. The supported modes are 2d6, 2d4, 2d8, 2d10, 1d12, 1d20, a deck of cards, a single hex number, a single 8-bit binary number, or an eight character alphanumeric password. It’s more than enough for D&D or when you really need an unguessable password. Video demo below.

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A PIC Powered Pair Of Electronic Dice

[Timothy] is honing his microcontroller skills with this electronic dice project. In addition to giving him an opportunity to work on some code, the use of an 8-pin chip provides a design challenge for driving the twelve pips and providing a user input.

The project started off with some $4 strings of LED Christmas lights. He promptly disassembled the strands, each yielding 100 LEDs. The microcontroller he chose to work with is a PIC 12F629. It’s DIP8 package provides six I/O pins to work with. When examined closely you will find that the pips on a die are always present in pairs with the exception of the center pip. This means that only four pins are needed to drive one die. You can see a pair of transistors above; one is a PNP, the other an NPN. These are both driven from the same uC line, which toggles between the pair of die. This accounts for 5 of the available pins, with the sixth monitoring the push button.