Such a waste of faces :). Give a tetrahedron's faces 0,1,2, and 4 pips and throw it into a v-shaped groove so that it lands on an edge. (This is also a solution to numbering the corners of a cube).
tromp [3 hidden]5 mins ago
So you get, with equal probabilities, 0+1, 0+2, 1+2, 0+4, 1+4, or 2+4 = {1,2,3,4,5,6}. Same as 2:07 in the video, but using only 1/3 of the faces. Brilliant!
robinhouston [3 hidden]5 mins ago
I'm (pleasantly) surprised to see this on the front page of HN!
I first discovered the result computationally, using a program written in https://sentient-lang.org/, before finding the ‘human’ proof described in that PDF.
oatsandsugar [3 hidden]5 mins ago
This is glorious. What a world we live in.
How can we make a die that functions as a d6, but has "less pips". An elegant dodecahedron as the solution. Less pips but more sides. Not an economic solution, but I love that these problems are being solved.
hinkley [3 hidden]5 mins ago
That is the nerdiest thing I’ve ever seen and it’s appropriate that he was wearing a top hat while presenting it.
However, the point of dice is typically not so you can count the numbers but so others can count them. People sitting at a table with you cannot see “up”, they can only see from an angle and so these dice while mathematically cool are completely impractical. Great example of white tower design.
mkl [3 hidden]5 mins ago
The article points this problem out. It's recreational mathematics, not intended to be practical.
Or a d6 with the 4, 5 and 6 faces blank. When you roll, if the face isn't blank, that's your number. If it is then flip the die over and subtract that number from 7.
Only uses 6 pips.
ejddhbrbrrnrn [3 hidden]5 mins ago
Pip position encoding can get that down to 3. One pip on 3 adjacent sides.
Centre pip = 1, Edge = 2, Corner = 3
quirino [3 hidden]5 mins ago
If we're gonna go that route, you can just put a single pip on a corner and derive all of the other positions from that.
gcr [3 hidden]5 mins ago
Nope, that’s rotationally symmetric around the (pip, center of dice) axis.
Put the pip on the face, but near the corner.
pavel_lishin [3 hidden]5 mins ago
This would be a fun video to send to your DM before showing up with these dice.
hinkley [3 hidden]5 mins ago
Oh no a boulder fell on your character. 200 points of crush damage.
If anyone really wants to nerd out on the rhombic triacontahedral die, my proof of uniqueness is at https://s3.boskent.com/rhombic-triacontahedron-die/uniquenes...
I first discovered the result computationally, using a program written in https://sentient-lang.org/, before finding the ‘human’ proof described in that PDF.
How can we make a die that functions as a d6, but has "less pips". An elegant dodecahedron as the solution. Less pips but more sides. Not an economic solution, but I love that these problems are being solved.
However, the point of dice is typically not so you can count the numbers but so others can count them. People sitting at a table with you cannot see “up”, they can only see from an angle and so these dice while mathematically cool are completely impractical. Great example of white tower design.
https://en.wikipedia.org/wiki/Razzle_(game)
Only uses 6 pips.
Centre pip = 1, Edge = 2, Corner = 3
Put the pip on the face, but near the corner.