Rearrangement / Permutation

This section is devoted to puzzles having similar pieces which must be permuted, often as groups, in order to progress from a random state to a solved state. This group forms a sub-class of the general class of "Sequential Movement" puzzles. Achieving any given state, or arrangement, depends on previously achieved states and sequences of movements, often known as "operators."

Many of these puzzles are mass-produced (or hand-crafted modifications to a mass-produced puzzle), colorful and made of plastic. There are a few sub-categories, the first of which is the "Twisty Polyhedra." Every puzzler knows about Rubik's Cube, the quintessential representative of this group. These puzzles are in the form of a Platonic or an Archimedean solid, "sliced" along various planes to permit certain axes of rotation of pieces or groups of pieces. They contain clever internal mechanisms which keep the moving pieces coherent. (You can see many patents showing the mechanisms at Joshua Bell's site.) A lot of group-theory mathematics applies to this category.

There is also a sub-category where the moving pieces are essentially grouped in two halves which can move relative to each other and exchange pieces - the Dihedral group.

Another sub-category includes the 3-Dimensional Sliding Block/Ball/Hole puzzles.

These are the websites I consider to be the reference for these types of puzzles:

Twisty Polyhedra

The illustration above shows many of the twisty polyhedra puzzles that are now or have in the past been mass-produced and commercially available. The illustration below is my attempt to provide a fun "map" of the Twisty Polyhedra puzzle landscape, including most of the commercially produced puzzles as well as several of the interesting hand-made custom modifications. I have exercised personal judgement as to what to include or exclude, and though I have tried to be comprehensive there is no way I could be complete. Sadly, I own copies of only a small portion of these puzzles. Photos are from several sources, including Sandy's TwistyPuzzles.com, Jaap's Puzzle Page, and Hendrik Haak's PuzzleMuseum.

The basis of the map is a central pentagon, having the five regular Platonic solids at its vertices (the yellow circles). At the center of each vertex circle is the key commercially produced puzzle having that shape. Those and other key commercially produced puzzles are outlined in red. Spherical puzzles radiate outward from the center of the pentagon. For the most part, derivatives of the key puzzles are shown near their relations, though some placements may be problematic. Some interesting cube sticker variations and bandaged cubes are shown in the upper left, and cube derivatives in the upper right. The families of derivatives of the Skewb and the Square-1 are shown in bubbles on the left. A group of rhombic octahedra appear on the right, and a group of dihedral puzzles in the lower right. Radiating "arms" show the different sizes of Rubik's Cube, and puzzles related to the Dino Cube.

The next section contains several definitions. You can click the "_" symbol to hide it, if you'd like.

Definitions:

  1. The basic form of a "twisty polyhedron puzzle" is a polyhedron (MathWorld, Wikipedia), although rounded shapes are traditionally included in the class, for example spheres, and cylinders or pucks (or "UFO"s).
  2. Polyhedra have been studied extensively since antiquity and formally classified, based on their features, and whether they are convex or concave (non-convex). For a comprehesive list, see George Hart's Encyclopedia of Polyhedra, or the Wikipedia page for Polyhedron. Only a few shapes have been used again and again as the basis for twisty polyhedra puzzles. Some have only appeared in custom puzzles. Polyhedra that are too spiky, too rounded, or too irregular might be of interest to a collector but probably won't make popular puzzles as they are difficult to handle and/or too difficult to visualize when solving.

    • The five Platonic Solids (regular convex polyhedra) - tetrahedron, cube, octahedron, dodecahedron, and icosahedron - have proven to be the most popular shapes, though the icosahedron is infrequently used.
    • There are four Kepler-Poinsot (regular non-convex) polyhedra - These shapes are also the result of stellation of some Platonic Solids. The tetrahderon and cube have no stellations. The octahedron has one stellation, called a stella octangula - that shape has appeared in the Starburst and the Dino Star. The dodecahedron has three stellations: the small stellated dodecahedron, the great dodecahedron, and the great stellated dodecahedron. Only the great dodecahedron has been used in a commercial puzzle - the Alexander's Star. There are 59 stellations of the icosahedron, one of which is the great icosahedron.
    • Some of the Prisms and Anti-Prisms have been made. The larger category here is Prismatoid polyhedra, which also includes pyramids, cupolas, frustums, and wedges. There are also several varieties of Bi- or Di-pyramids.
    • Of the 13 Archimedean (semi-regular convex) polyhedra, the truncated tetrahedron, cuboctahedron, truncated cube, truncated octahedron, rhombicuboctahedron, and truncated icosahedron (soccer ball) have appeared.
    • The 13 Archimedean Duals, or Catalan Solids have not been much used, except for the rhombic dodecahedron and rhombic triacontahedron. There are three stellations of the rhombic dodecahedron, the first, second, and third. These shapes have been used more for interlocking puzzles than twisty puzzles.
    • The 92 Johnson Solids have not been used much at all.

  3. A polyhedron becomes a twisty puzzle when it is cut into distinct pieces, and an internal mechanism preserves the coherence of all pieces while allowing groups of one or more pieces to be moved (a twist). After a move or twist, pieces have exchanged positions with other pieces and potentially changed their orientation. The objective of the puzzle is to mix up the pieces, then restore them to a specific target configuration.
  4. There are a variety of cutting schemes and internal mechanisms ("cores") that have been developed. You can see many of the relevant patents at Joshua Bell's website. Most mods are based on commercially available puzzle cores, though with the broader availability of improved design tools such as CAD and 3D printing, new and more complex mechanisms are easier to realize (such as those used in the Pentultimate and the 24 Cube).

    It may be better to classify puzzles by their use of internal mechanism, but I'm not sure I like that method. I think it's more interesting to challenge designers by specifying a shape, slicing format, turning mechanics, and other features, then let them figure out the necessary internals. Of course, this does make it hard to chart the various mods made from non-standard mechanisms such as the Square-1, or adaptations of the mechanism for one shape to make a different shape, resulting in weird asymmetric cuttings (Tony Fisher's Hexaminx - a cubic Megaminx - comes to mind). Chris Lohe has a nice, though not exhaustive, chart at his website, organized by mechanism versus shape.

    Here are several mechanisms and/or cutting formats:

    • Cuboids
      • AxAxA - A=2,3,4,5,6,7
      • AxBxB - 1x2x2 (Morph), 1x3x3 (Okamoto's Floppy Cube), 2x3x3 Domino, 3x2x2 Slim Tower and Franken Tower, 3x4x4 Specter and Chaos, 4x2x2 (Fisher 2003), 4x3x3 Phantom Cube, 5x3x3 Grown Tower and TF 2004, 5x4x4 TF 2003
      • AxBxC - 1x2x3, 2x3x4 Step Up Tower and TF 2003, 2x4x5 Chaos
      • These can be made in fully functional, extended, or "chaos" (multiple core + extended) forms.
    • The EastSheen A4 cube core allows interesting overlapping effects
    • Pyramorphix
    • Pyraminx/Skewb
    • Dino/Stella Octangula
    • Helicopter/Bevel
    • Hybrid
    • Chop (e.g. the 24 Cube)
    • Megaminx
    • Dogic
  5. Key features of a polyhedron include faces, vertices, and edges. Most twisty polyhedra puzzles will have different types of pieces corresponding to each of these features. A given face may have one or more center pieces, edge pieces (shared between faces), and corner pieces (again, shared between faces). Almost always, an edge joins two and only two faces, and the corner pieces (if present) are at vertices of the polyhedron. Faces and edges meet at a vertex, and define a particular vertex figure.

    A design or variant might be contrived to disguise or eliminate centers, corners, or edges or combinations thereof. This may necessitate allowing pieces to overlap as they turn past one another as the trajectory of the cut on the surface of the puzzle no longer follows the linear path of a great circle equivalent. This will differentiate one puzzle from another otherwise of the same order, and dictate different solution methods. I use a 3-letter code to represent the design scheme, as follows:

    • CEC = corners edges centers all present
    • CEN = no centers
    • CNC = no edges
    • CNN = no edges and no centers
    • NEC = no corners (this is what people usually mean when they say "edges only" though technically centers are present, too)
    • NEN = no corners and no centers
    • NNC = no corners and no edges - faces only
  1. Members of this puzzle category are distinguished from their Sliding Piece brethren in the Sequential Movement class in several ways. For twisty puzzles, pieces move in distinct groups. There is no frame and there are no levers or plungers. Also, the space of possible states is typically very large and it is unreasonable for a person to navigate directly from a mixed state toward a solved state (i.e. using "God's algorithm") - instead, a variety of operators or algorithms (i.e. specific sequences of particular twists) must be used in series, each of which accomplishes a subgoal leading towards better order by moving subsets of pieces in determined ways while leaving other subsets undisturbed. Expert solvers have memorized many useful operators, can quickly recognize patterns or states when a given operator will be useful, can keep track mentally of where they are in the midst of a sequence of moves, and can apply operators (sequences of twists) very rapidly with great manual dexterity. Sometimes operators learned for one puzzle can be useful on another type, but often a distinct set of operators must be learned for each different puzzle type.
  2. A Deep Cut puzzle's cuts divide it into halves. Otherwise, the puzzle is Shallow Cut, though there are gradations of shallowness, and some puzzles might have a few deep cuts mixed with shallow cuts. Alternatively, circumscribe a sphere around the puzzle, and project the cutting planes to intersect the sphere. If the projections make great circles on the sphere, the cut is deep. This disqualifies the Pyraminx ( Pyraminx setting on Jaap's Sphere) but includes the Skewb ( Skewb setting on Jaap's Sphere). Read a debate about the definition of "deep cut" in the TwistyPuzzles forums.
  3. If the cutting scheme results in sets of regular pieces, essentially interchangeable within their groups, then it is customary to distinguish them by coloring their individual faces. The overall pattern of colors will define the goal state of the puzzle. In other cases when the pieces are distinctly proportioned, the puzzle might be monochromatic and its goal state defined by shape alone.
  4. I've defined the order based on the number of parallel cuts (either deep or shallow) between opposite pairs of faces, vertices, or edges, or for tetrahedrons, opposing face-vertex pairs. Note that for some shapes, the count of parallel cuts does not increase linearly. Also note that the term slice is used ambiguously to mean either a cut itself, or a layer between two cuts or between a cut and the surface of the puzzle. My definition of order might be at odds with they way some people think about these puzzles - for example I define the 2x2x2 Pocket or Mini Cube as order 1 but some might define it as order 2 based on it having two "slices" in each dimension.
  5. Note that it is possible to construct puzzles with asymmetric slicing schemes - i.e. different numbers of parallel cuts between different pairs of opposite features. These would be characterized using compound orders.
  6. It is also possible to arrange the cuts so that they are either equally or unequally spaced between the features that bound them - the resulting slices are correspondingly either equal or unequal.
  7. Another irregularity results when not all opposite features have the same set of cuts between them, though those that do, have the same number of cuts between them - i.e. subsets of opposite features are treated differently. I call this a Partially Cut puzzle and distinguish it from a Fully Cut puzzle. This can be a consequence of creating a shape modification with a particular underlying core mechanism originally clothed in a different shape. An example is the dodecahedral Skewb Ultimate which has a Skewb core, originally clothed in a cube. The cube has eight vertices, and in the Skewb every pair of vertices has one (deep) cut between them, so four cuts suffice. The dodecahedron has 20 vertices or 10 pairs of opposing vertices. Since there are only four (deep) cuts, there is a cut between each of only four out of the ten pairs of opposing vertices.
  8. If all the pieces in a face move during a twist, the puzzle is Face-turning. If instead all the pieces around a vertex move, the puzzle is Vertex-turning. Similarly, if all the pieces along an edge move, the puzzle is Edge-turning. Hybrids are possible, but the internal mechanisms become complex, and the puzzle becomes very "floppy" since it is difficult to hold without inadvertently twisting something.
  9. In tetrahedra, the distinction between face and vertex turning is blurred, since a vertex is opposite a face. A more useful distinction is whether cuts divide edges into equal parts or not.
  10. Only a few of the many possible species of twisty polyhedra puzzles have been realized; fewer still have made it into mass production, and even fewer remain readily commercially available. Many of the more esoteric shapes and cutting schemes, when they exist, are hand-made modifications or "mods." The art of "twisty modding" has advanced considerably only recently.
  11. A sphere has no faces, vertices, or edges. A more useful distinction is how the cuts divide the surface, and how they intersect. The cuts can make great circles or small circles. By convention, two points at diametrically opposite locations on an arbitray great circle are chosen as poles. All great circles passing through the poles are longitudinal. One great circle can perpendicularly bisect all longitudes - this is the equator. Small circles parallel to the equator are latitudinal. Symmetrically arranged small circles are typically centered on regular polyhedra inscribed within the sphere.
  12. A cylinder or puck has two parallel circular faces with a curved surface between them. Cuts can be radial and divide the circular faces, or sectional and lie between the faces.
  13. So to classify the various species of twisty polyhedra puzzles by their physical characteristics, one could use the following criteria in some priority:
    • Shape
    • Order
    • Turning type - Face, Vertex, (Face/Vertex for tetrahedra), Edge, Hybrid
    • Cutting style - Deep vs. Shallow, Equal vs. Unequal, Full vs. Partial, Symmetric vs. Asymmetric; for spheres, layout of longitudinal, latitudinal, and small-circle cuts; for cylinders/pucks/ufos, layout of radial and sectional cuts
    • Features - Corners/Edges/Centers present?
    • Internal core mechanism
    • Decoration/coloring scheme

    One could additionally or alternatively use the total number of unique possible permutations or states, or some (subjective) rating of difficulty, or of rarity.


Here are a series of charts I made to organize my thinking about the relationships among various puzzles of each Platonic shape.





A while back I snagged a Usenet post of a list compiled by Mark Longridge (March 22, 1996) in which rearrangement puzzles were ranked by number of combinations. That list gave me the idea for the organization scheme of the table below. Jaap's Puzzle Page was invaluable in teaching me what puzzles were out there, and for providing combinations data for several puzzles, allowing me to add them to the table at the apropos rank. I include a few puzzles I do not own, for reference - they will be noted as such.

The number of permutations, positions, or states a puzzle can achieve is not always a good indicator of difficulty. Many cubers rank the Square-1 as more difficult to solve than many puzzles with larger numbers of permutations. I have not attempted to rank the puzzles by difficulty.

My favorites include the Pyraminx (I worked out solution procedures myself), the Square 1 (I wrote a program to explore moves), the Impossiball (I've had it for a long time though I've never solved it, and I love its organic motion), and the Skewb (its motion is so precise). I also like the Orb[-it]. I got a Masterball in Japan and the Tonne in Germany.

 

Puzzle Name and Notes Positions Mechanism
Teraminx, Petaminx
(Custom puzzles - included for reference to show number of positions - I don't have these.)
Teraminx: 1.16*10525
Petaminx: 3.16*10996
Teraminx, Petaminx: Drew Cormier
Gigaminx 3.65*10263 Originally realized by Tyler Fox. Subsequently made by others. Commercially released by James Lee at Cube4you (also Cubefans).
V-Cube 7
from Verdes Innovations.
1.95*10160 Panagiotis Verdes
V-Cube 6
from Verdes Innovations.
1.57*10116 Panagiotis Verdes

Dogic
Original version (with box), Mefferts I (12 color), II (10 color), and VI (20 color). I don't have Mefferts III (5 color) and V (2 color).
Jaap's page
2.199*1082 Zoltan and Robert Vecsei
5x5x5
Rubik's Wahn
Professor Cube
also Eastsheen A5 (a different mechanism)
2.8*1074 Udo Krell
6-armed spider


Megaminx
(Tomy version, Meffert's tiled version, Hungarian Supernova re-issue, tiled Chinese version, stickered black Hong Kong version, stickered white Hong Kong version)
Also the Holey Megaminx from Mefferts (in black and white), designed by Lee Tutt.
1.0*1068 (12 color version)
6.144*1063 (6 color version)
Kersten Meier
Ben Halpern
12-armed spider
Meffert's Pyraminx Crystal
First patented in 1987 by Uwe Meffert: DE8707783 (U1).
Katsuhiko Okamoto had created a version he called the Mega Crystal.
Aleh Hladzilin created a version he eventually named the Brilic - he made around a dozen, some of which sold for over $1000. At first he used a Dogic core, then later a Megaminx core.
Noah Hevey has written a nice history of this puzzle - see topic 85537 in the TwistyPuzzles forums. Also see thread 7711 for a discussion of solution methods.
While a twist on the Megaminx moves 5 corners and 5 edges, a twist on the Crystal moves 5 corners and 10 edges.
1.68*1066 A build-up of the Megaminx, without centers.
Mozaika 6.27*1049 Rudolf Destics
4x4x4
Rubik's Revenge
also Eastsheen A4 (a different mechanism)
7.4*1045 Peter Sebesteny
grooved sphere
The Ball.B
From Poland - website here. This shape - a spherical Megaminx (aka Ballminx) - was first explored by Jürgen Brandt.
The version with dots is like an edges-only Megaminx, since for this version the corner orientations don't matter.
7.12*1040
The version with flags is equal to the Megaminx.
?
Alexander's Star
(Equal to a Megaminx with no corners and no centers.)
7.2*1034 Adam Alexander
Face-Turning Octahedron

(compared to the Magic Octahedron)

8.49*1028 ?
Logi-VIP 2.7*1025 1982 Logitoy AG, Austria
Hubert Petutsching
Patent WO8101638


The Thomasball is essentially
the same but with a different mechanism
Impossiball
(Equal to a Megaminx with no edges and no centers.)
2.4*1025 William O. Gustafson
Wolfgang Kuppers
3x3x3 Picture Cube
4 distinct orientations
for all centers
e.g. Hoey's Tartan Cube
I don't have this.
1.772*1023 ?
8.8*1022
Erno Rubik
Dan Hoey

play with a virtual calendar cube here
Rubik's Perpetual Calendar
(Kalender Kubus)
The "O" character on one
center has only 2
distinct orientations
4.4*1022 Marvin Silbermintz
Super Square 1 (4-layer)
Produced by cube4you. See this thread at the cube4you forums.
Watch a video.
1.19*1022 ?
Rubik's Cube 4th Dimension
Four centers must have distinct orientations
1.1*1022 Erno Rubik
Fisher Cube
An axis-rotated 3x3x3 (single axis x 45 degrees)
Solve as a 3x3x3, but also has four of six face centers that can be rotated by 90, 180, or 270 degrees. Algorithms exist to rotate a single face center by 180, or a pair - one by 90 and another -90.

U180: ( (U R L U2) R' L') x2

U90 & F-90: F B' L R' - U D' F' U' D - L' R F' B U

U90 & D-90: R L' F2 B2 R L' U R L' F2 B2 R L' D'

1.1*1022
Same as Rubik's 4th Dimension?
Tony Fisher
(33 core)
Mefferts "Master Pyramorphinx"
Commonly known as a Mastermorphix (a curvy version)
Available at Meffert's.

During solving, you might end up with one center that needs a 90 degree rotation. Turn the entire face so the center is correct, then re-solve that face.

?
This is a 3x3x3 mod, but center orientations matter.
6-arm spider
Rubik's World 2.7*1021 Erno Rubik

Masterball (Geomaster, aka Rainbow version), Duo B&W, Dragon, Circus, Soccer

See other versions at Les Casse-Tete de Chantal

Mullen & Robinson solution

4.1*1020 Dr. Geza Gyovai patent 4856786


3x3x3 Rubik's Cube
Solutions here.
Rubik's Ball and the Cuboctahedron are essentially the same.

The Morph Egg is from Meffert's, designed by Adam Cowan.

Algs for moving edge from bottom to FL:
Start in FD matching F: D L D' L' - D' F' D F
Start in LD matching L: D' F' D F - D L D' L'

Algs to finish bottom corners
(begin by positioning 2 or 4):
Swap adjacent front bottom corners: {R'D' R F} D {F'R' D R} D2
Swap front left bottom diagonally: {R'D' R F} D2 {F'R' D R} D
Leave front left, turn other 3 CCW: R' D' R D' - R' D2 R D2
CW (inverse of above):
D2 R' D2 R - D R' D R

Algs for fixing bottom edges:
3-cycle (if one is in position, hold it in front): L'R - F - LR' - D2 - L'R - F - LR'
or, where ( means L'R, and ) means LR':
(F)D2(F)
flip DL & DB: L'R - F - LR' - D' - L'R - F' - LR' - D' - L'R - F2 - LR'
or
(F)D'(F')D'(F2)
You may have to repeat these 2 algs in sequence.

4.325*1019 Erno Rubik
6-armed spider
Rubik's Mirror Blocks (aka Bump Cube)
designed by Hidetoshi Takeji.
The Bump Cube was entered in the IPP 2006 Design Competition. The hand-crafted version had been for sale at $320.
I got one boxed copy signed by Hidetoshi-san.
(Same as 3x3x3 cube.)  
Trajber's Octahedron
Purchased from David Calzone. David made a batch by casting pieces molded from 3D-printed masters. The Trajber's Octahedron is a vertex-turning puzzle and has a 3x3x3 cube core. The group shot shows various kinds of octahedral twisty puzzles - the vertex-turning Magic Octahedron, the Trajber's, Meffert's Skewb Diamond (face-turning), and a new face-turning octahedron from Taiwan (the next higher order from the Skewb Diamond):
4.05*1019 ?
Truncated Trajber's Octahedron
Made by Tanner Frisby.
? ?
Dodeca Nona
A faces-only dodecahedron.
This type of 3D edgematching puzzle is included here because I consider them "faces-only" versions of twisty polyhedra - no corners and no edges.
12 magnetic pentagonal 2-sided tiles fit to the faces. Each face has the numbers 1 through 5 arranged around its corners - all 24 possible arrangements are included. Place the tiles so that at every vertex of the dodecahedron, the numbers add up to nine.
3.99*1018
1122 solutions.
?
The Void Cube, designed by Katsuhiko Okamoto.
Manufactured by Gentosha Toys. Purchased from Torito.
The Void Cube won the Jury Grand Prize in the IPP 2007 Design Competition.
When solving the Void Cube, you might run across a parity problem.
To see the internals, see this thread on TwistyPuzzles.
1/12 of a normal 33
3.60*1018
Katsuhiko Okamoto
Tantrix The Rock
A truncated octahedron.
This type of 3D edgematching puzzle is included here because I consider them "faces-only" versions of twisty polyhedra - no corners and no edges.
Tantrix Home Page
Jaap's page
1*1018
"over a billion billion"
?
Mobius
This type of 3D edgematching puzzle is included here because I consider them "faces-only" versions of twisty polyhedra - no corners and no edges.
? ?
Octagonal Prism
Jaap's page
4.5*1017 ?
Magic Octahedron 2.0*1015 (not including the trivial tips)
8.23*1018
?
Christoph's Magic Jewel
(a Pyraminx Octahedron
minus the tips)
I finally found one at IPP 29 in SF.
  Christoph Bandelow
6-armed spider
Square 1 1.2*1013 Dr. Vojtech Kopsky


I have three knock-offs
one is broken :-(

3x3x2
Rubik's Domino
4.0*108 Erno Rubik
Rainbow Cube
Comes in 7-color and 14-color versions.
Jaap's page
2.4*108
239,500,800
Bethel Japan
Skewb Ultimate
Jaap's page

The Skewb Ultimate is the "most difficult" of the Skewb family - every piece has a proper orientation, unlike, for example, the face centers on the Skewb.

The hierarchy is:
PositionsMoves to
Antipode
Puzzle
100,776,96014Skewb Ultimate
3,732,48012Halpern-Meier Tetrahedron
3,149,28011Skewb
933,12011Pyraminx
138,24010Skewb Diamond
2,1606Meffert's (4 color) Beachball

1.0*108 Uwe Meffert
Rubik's UFO 4*107 Erno Rubik


Jaap says these are analogous:

Mefferts Jackpot, NGP, and Hoberman Braintwist

Dino Cube #1
6-color each side different
I don't have this Dino version.
1.9*107 ?
Dino Star (blue) ? Dino Cube core
Halpern's (Halpern-Meier) Tetrahedron
(Also comparison with Skewb.)
This was produced commercially - but I have a custom-built example made by Matt Davis from cast pieces and a Skewb keychain core.

Solve as a Pyraminx, then fix centers.
My operator to flip two edges in place: L T' R T R' T L' T'

When 3 edges around the top would be solved if only you could circulate them clockwise: (R T' R') T' (R T' R')

Fix centers - swap F-L and R-D: (T' R' T R)*3

3.7*106
3,732,480
Ben Halpern
Kersten Meier



2x2x2
Pocket Cube
Jaap's page

Algs to finish bottom corners
(begin by positioning 2 or 4):
Swap adjacent front bottom corners: {R'D' R F} D {F'R' D R} D2
Swap front left bottom diagonally: {R'D' R F} D2 {F'R' D R} D
Leave front left, turn other 3 CCW: R' D' R D' - R' D2 R D2
CW (inverse of above):
D2 R' D2 R - D R' D R

3.7*106
3,674,160
Erno Rubik
6-armed spider.
Quarks, from Fourier Idea, Inc.
Meffert's Fisher's Golden Cube
Perhaps the most famous of the Skewb mods, now produced commercially by Meffert.
? Tony Fisher

Skewb
Also various Skewb balls, and a white Skewb Egg from Meffert, designed by Tony Fisher.
Jaap's page
Meffert's solution.

L means twist around down-front-left corner
R means twist around down-front-right corner
B means twist around down-back-right corner

0) Pick a top face, get 4 corners around it irrespective of their rotation.
1) Swap top-front-left with top-back-right if necessary: LBL
2a) Rotate TFL CW: LR L'R'
2b) Rotate TFR CCW: R'L' RL
3) Rotate bottom corners - depends on position of bottom-color facelets:
3a) None done: hold so 2 bottom-color facelets face right: LR'LR' L'R L'R
3b) Two done: hold so one not done is at DFR: do alg above, then do 3a.
4) Fix faces: swap F w/ D and L w/ R (fiddle combos until done)
if 3 faces in a row are done, hold them L-B-R
if 3 faces around a corner are done, hold them L-T-B
[LR' L'R]x3

3.1*106
3,149,280
Tony Durham
Einstein Cube
A faces-only cube (granted, the faces are rounded).
This type of 3D edgematching puzzle is included here because I consider them "faces-only" versions of twisty polyhedra - no corners and no edges.
12 positions per face. A similar puzzle called "Turn Twelve" has 24 positions per face.
12^6 = 2,985,984 (Einstein w/ 12 pos./face)
3*106
24^6 = 191,102,976 (Turn 12)
1.9*108
?
Diamond Cube
Jaap's page
2.0*106
2,425,500
?
Bandaged Cube
Jaap's page
Andreas Nortmann has investigated bandaged cube variations - read his article (thread 3217) in the TwistyPuzzles forum. He says there are 7336 different bandaged cubes.
1.0*106
1,108,800
?
Pyraminx
My operator to flip two edges in place: L T' R T R' T L' T'

When 3 edges around the top would be solved if only you could circulate them clockwise: (R T' R') T' (R T' R')

9.3*105 933,120 (not including trivial tips)
7.6*107
75,582,720 (with tips)
Uwe Meffert
4-armed spider
Tetraminx
(A Snub Pyraminx - same as Pyraminx with trivial tips removed.)
Mefferts version, and transparent version from Smaz.
  Uwe Meffert
Brainbow
Jaap's page
623,760 ?
Skewb Diamond
(also a clone, in white)
Jaap's page
138,240 Uwe Meffert


The Starburst is a custom mod.

Pyramorphix
aka Pyramorphinx
Jaap's page
I find I can solve the Pyramorphix using only four operators (beyond fiddling to get it into a tetrahedron shape and properly position the corners):
  • Move the bottom face down: D2 R2 L2 R2
  • Exchange the left and right faces: R2 L D2 R L2 D' (this twists corners,too)
  • Twist Up corner clockwise: (R L' R' L)x2
  • Twist Up corner counter-clockwise: (L' R L R')x2
136,080 Rubik, Barry Lockwood

There are four versions of the Dino Cube:

2 colors
312.55/1

4 colors
528.99/1;535.55/1

6 colors, no dinos
337/1

6 colors, with dinos
667.96/1
Dino Cube
4 color version
I find this very easy to solve even without operators.
The four Dino versions shown for reference. I've only got the 4-color, but the others are just sticker variations.
42,000 ?
Tonne ? ?
Mefferts Beach Ball (4 color Skewb ball) 2160 Skewb
Morph (1x2x2) Only 6 positions possible!
I find this harder to mix up than to solve.
?
4D8 ? ?
PyraDiamond, Meffert's version of the Okki/Gem ? Pyramorphix
GloBall
See GloBall variants here.
? ?

Dihedral / Non-Polyhedral

This section contains dihedral puzzles - puzzles whose halves can move relative to each other and permit the exchange of pieces between them. Their shapes aren't convex polyhedra, nor simple spheres, cylinders, or pucks.

Puzzle Name and Notes Combinations
Smart Alex
Dumitru A. Pop, patent on 26 May 1992
Jaap's page
6*1020
Octo Bracelet 3.7*1018 (?)
Sando Ring
(aka King Ring)
4.97*1014
Tricky Disky
Jaap's page
2.1*1013
Hungarian UFO 2.1*1013
Brainball
Andreas Unsicker
Jaap's page
2*1012
Netblock UFO
Wai K. Chan
2.0*108
200,121,075
Gerdig UFO
Gerhard Huncaga
Jaap's page
130,040

Group shot:
Roundy
(4-leaf/4-color version)
Purchased at IPP28 in Prague.
40320
Roundy
(3-leaf/6-color version)
Fritz Gruber
12/7/93
patent 5267731
23040
Saturn
Jaap's page
5040
Roundy
(3-leaf/3-color version)
Fritz Gruber
12/7/93
Jaap's page
2880
Clever Disk ?
Sphere XYZ ?

Variations and Custom Puzzles

This section contains variations of puzzles, and custom-built puzzles.

You can hide the following notes by clicking the "_" button.

Notes About Sticker Variations

A 33 has 26 cubic units visible on its surface - 8 corners, 6 face centers, and 12 edges. Each corner exposes three "facelets" - each face center one, and each edge two, for a grand total of 8x3+6x1+12x2= 24+6+24 = 54 facelets, each of which is usually covered with one sticker. In the standard configuration there are nine stickers of each of six different colors, and each of the six faces of the cube is stickered with a solid color. The basic sticker pattern has varied with respect to the six colors used and how they are arranged relative to each other. In addition, one or more stickers might bear a logo of some sort.

The cube is usually made from black plastic, but has appeared in other colors. A collector will have to decide if color variations of the body material are worth collecting for their own sake.

The corners and the edges permute in separate groups. Furthermore, the six face centers of the basic 33 are fixed relative to each other and do not permute.

a) Corners can be "twisted" among 3 orientations
b) Face centers can be twisted among four orientations
c) edges can be flipped between 2 orientations

As the cube is twisted, the units permute within their groups, and the color arrangement becomes scrambled. The objective of the puzzle is to unscramble a scrambled cube, restoring the canonical color pattern on all faces simultaneously.

Sticker variations can serve four basic purposes:
1) pure decoration
2) advertising promotion
3) modify the difficulty of the basic coloring, without changing the basic objective of restoring a canonical pattern
4) alter the goal of the puzzle (e.g. calendar cube, sudo-kube)

Personally, I am uninterested in sticker variations of the 1st or 2nd varieties, except insofar as they simultaneously accomplish the 3rd or 4th purpose.

The "standard" stickering actually reduces the potential difficulty by making (b) unimportant - all face center orientations are indistinguishable. However, (a) and (c) are important. Some sticker variations can make (b) important, by making it possible for from one to all six of the face centers to have two or four distinct orientations. Some sticker patterns go further and add confusion by making the individual units and/or their proper orientations very difficult to visually distinguish.

Notes About Twisty Mods

To "mod" or modify a twisty puzzle is to create a customized version of a puzzle, usually by starting with one of the commercially available puzzles and making various modifications, or sometimes by building a new variety from scratch.

New custom puzzles will continue to be made and there will always be some new design-of-the-hour not covered here. To keep abreast of the latest developments, you should monitor the Twisty Puzzles forums.

Here is where to go to see additional custom-design puzzles:

Some designs will make it into production while others will be forgotten or remembered only as impractical curiosities. Artists will come and go, and pass away.

There are several people who have become fairly well-known in the twisty puzzle community for their custom creations, and many creations which have become recognized as "classics."

There has been a recent flowering of new custom-crafted designs, brought on by broader knowledge of and availability of CAD design tools that can output STL (e.g. Solidview, Alibre, CoCreate by PTC, 3D Studio Max by Autodesk, Kompas-3D from Ascon, ViaCAD from Punch, VariCAD, BRL-CAD, others listed on Peter Eland's site ) (see Tyler Fox's tutorial on YouTube - part 1 - turn up the volume all the way), 3D printing services (e.g. 3dpartz.com, fdmonly.com, Shapeways, printo3d.com) that can take STL input and make master parts, and materials and techniques for casting parts from polyurethane plastic resin (e.g. Conap, Alumilite - get some at Hobby Engineering) using silicone rubber (e.g. Oomoo 25 or 30 - longer pot life, but longer cure time) two part molds poured in a Lego box. Don't forget a mold release agent such as Mann Ease Release 800 or 200. See the articles at TwistyPuzzles. Also this thread.

The traditional methods include cut-downs using a Dremel or hacksaw, and build-ups using Apoxie Sculpt (also here), Milliput, 1/8" ABS plastic sheet, or .040" polystyrene sheet. You can find materials at McMaster.

Many mods will use a black DIY core.

Use a Stika or some other vinyl sheet cutter (e.g. US Cutter) to create the stickers from Oracal 651 vinyl adhesive sheet.

Some of the amazing custom creations:

Scott Bedard has created a cooperative site named bedardpuzzles.com where some of these puzzles will be available for sale.


Puzzle Name and Notes
Tony Fisher's Mental Block
3x3x1
aka Rubik's Layer
Custom-made by Tony, from a full-sized Skewb
Floppy Cube
3x3x1
Custom-made by Katsuhiko Okamoto
This won First Prize at the IPP26 Design Competition.
Now available commercially from Gentosha.
A 1x2x3 by Scott Bedard.
Fisher's Cube / Diagonal Cube
8-color sticker variant
A fully functional 2x2x3 - this mod is known as the "Slim Tower."
Double and Triple Cubes
Available commercially from various sources, made from keychain 2x2x2 cubes. Two cores share a corner in "Siamese" configuration.
King Pillow Cube
A commercially produced shape variation.
Confused Pillow cube from "Socube"
Ultimate Cube
A commercially produced sticker variation. I have an original in its packaging.
Truncated Rhombic Dodecahedron
This cube-variant is almost a rhombic dodecahedron, except the four-color centers are flat, not pyramidal. The three-color corners are pyramidal.
3x3x5 Extended Cube
This simple extended cube-variant has an extra piece glued to each of the nine facelets of two opposite faces.
3x3x4 Extended Cube
This simple extended cube-variant has an extra piece glued to each of the nine facelets of one face.
3x3x3 Extended to 4x4x4
This is a cheap and simple extended cube-variant from Hong Kong, not a 4x4x4 Evil Twin as the description led me to believe. Caveat Emptor!
James Lee at Cube4you (also Cubefans) has issued a fully functional 3x3x4, previously only available as an expensive hand-made custom creation. This is based on Jin Kim's design - get STLs by Tom van der Zanden at TwistyPuzzles.com Forums, thread #12134.
Mini Evil Twin
Designed by Mike Grimsley.

Axis Cube
Designed by Adam Cowan, made by Frank Schwartz.
I am very pleased to have finally obtained a Helicopter Cube from Adam! The Helicopter Cube was first discussed in the TwistyPuzzles forums in thread 6253 - a particularly rich thread in which several ideas, including the concept of jumbling as opposed to shape-shifting, were broached. (More discussion on jumbling: 13071, 11126 .) Katsuhiko Okamoto mentions that he had completed his equivalent Bevel Cube the previous month. Robert Webb extrapolates a rhombic dodecahedral puzzle and Matt Shepit hints of its realization - it will be Shepit's Rua. Various folks have discussed their attempts to make their own Helicopter Cubes: 13856, 13520, 12030, 12423, 11679.
An Icosaminx made by Matt Davis
A Super-Square-1 Star mod - Brett made it in all white then I swapped in the black pieces.
You can find on-line [dis]assembly instructions here.
An Edges-Only cube from "Smaz."
Nightmare Cube from Tanner Frisby
Pillowed Hexaminx from Traiphum Prungtaengkit, of Thailand
(Shown with Helicopter Cube)
From Traiphum Prungtaengkit, of Thailand, an Edge-turning Pyraminx! He calls it a Mastermorphynx.
Also shown compared to a curvy Mastermorphix and a Pyraminx.
An Extended Cube.
I bought the Dino-Rhombic Dodecahedron (DRD) DIY from Drew Cormier. This puzzle is a vertex-turning rhombic dodecahedron where all 4-part and 3-part vertices turn. It turns well, but due to a design issue the 3-part corners turn only counter-clockwise.
The Crazy 4x4 from mf8.

This cube was discussed on the Twistypuzzles forums in threads 14856 and 7918. You can see how this cube moves on YouTube here.

Unusual Permutation Puzzles

Here are other unusual and interesting takes on the permutation puzzle...


The Planets puzzle consists of four spheres arranged in a tetrahedron within a frame. The spheres have various craters in them and are contrived to interlock so as to only permit certain rotations depending on where the craters are at any moment. Rotate the spheres so that each side of the tetrahedron is a uniform color.

Cmetrick is from eLogIQ. There are 6.9*109 possible positions. Jaap's page eLogIQ has also released the Cmetrick Mini.

I got an Enigma from Norman Sandfield at the 2005 NYPP. He said the reason they've been so hard to find is that the firm that makes them only sells them in bulk for advertising promos. However, recently I've seen a color version for sale at the Puzzle-Shop. [Jaap's Enigma page]

This is a variant of the Enigma, a French puzzle called "Combinescion."

This is the Spectra, by Eng's I.Q. Co. Ltd. 1987. 3072 positions. Jaap's page

Hoppa Gula

Rubik's Clock

Rubik's Rabbits

Rubik's Pen by Ideal from 1982.

This is a Boomdas puzzle from Asia. It is an interesting take on the 2-dimensional sliding puzzle, but using a linking mechanism similar to that of the Muto Cube, and with no frame. One side is numbered 1 to 9, the other has a stylized drawing of a figure.

The Virus

Kinato Hex Pro (Warning: website requires Chinese character set) and Kinato Hex 7

Orbik

Kabalabda Ball

Magellan
This turns out to be based on the Four-Color Map Theorem. The objective is to ensure that all adjacent areas contain different colors on their wheels, on both sides of the puzzle at once.

Labyrint

Gear Up - designed by Oskar van Deventer
made by George Miller

Eggcentric - designed by Oskar van Deventer

Writer's Block - designed by Oskar van Deventer, purchased from Bits and Pieces.
Produced by RecentToys.
Use an included "key" to find a set of moves that extends all the pens, allowing the box to be opened and the pens to be reset. Reminds me of "Lights Out."


I have had a Columbus' Egg puzzle since I was a kid. U.S. Patent 4489944 - Hatakeyama 1984. I also still have the instructions, though the packaging is long gone. I have found very few references to it on the web (TwistyPuzzles has a version with different branding listed with no info) and have had to wade through a lot of unrelated material because of the name. The instructions say it was issued by HirschCo at 2633 Greenleaf Ave. Elk Grove Village, IL 60007.

Slider
Position
Cylinders
which move
Down1, 4, 5
Middle3, 5
Up2, 4, 5
To scramble the puzzle, when all 5 red segments are showing through the window, turn the egg small end down so that an internal weight moves to the small end. Push the slide one or two positions and turn the base several times. To solve, get the egg to stand upright on its large end. You have to line up all red segments in the window again. Each of the 5 cylinders has 10 segments one of which is red. So there are 105=100,000 possible states. The 3-position slider controls which cylinders turn when you turn the egg's base. The instructions say all turns should be clockwise. From my experience, sometimes the cylinders "misfire" or skip. Here is a movement chart from the instructions - the slider position is either up (towards the small end), in the middle, or down (towards the large end). Number the cylinders 1-5 starting from the small end.

One of these went for $150 on eBay.

3-Dimensional Sliding Piece Puzzles

There are many 3-dimensional sliding piece (or sliding block) puzzles. Some consist of a framework or container inside of which are movable colored cubes. In some, there are moving marbles or beads instead of blocks, and in some cases the frame itself can be re-configured. Usually there is a single "hole" which can be thought of as moving around. Sometimes, however, the moving frame accomplishes the permutations of the piece positions and no hole is needed. In yet another sub-category, there are flat plates which can overlay each other. Still another sub-category accomplishes permutation using pieces as segments of interlocking rotating disks.

Movable Gap, Rigid Frame

Pepsi Can
Start with an idea as simple as mapping a 15-like puzzle onto a cylinder. This puzzle has advertised several popular drinks.

Billiards 9-Ball
created by Joshua Frankel
3,628,800 positions
Jaap's page

Massage Ball
Otto Wu
patent on 14 Feb 1995
6.1*1019 positions
Jaap's page

Vadasz Cube (2x2x2 and 3x3x3 versions)
(Also 4^3, which I don't have.)

Minus Cube (Russian)

Varikon black

Peter's Black Hole
5.4*1027 positions
Jaap's page

Twistypuzzles.com has an article by Ad van der Schagt titled "The History of Sliding Block Puzzles Before Peter's Black Hole" (PDF).


Clark's Cube

I-Qube

This is called the "Switch" or the "Knox Transposition Puzzle." It was issued by Mag-Nif in 1970 and also appears in their "Game Chest" set. The pegs slide in channels in the base. The object of the game is to exchange the sets of colored pegs in 24 moves or less. This actually borders on a non-jumping (exchange-only) type of Peg Solitaire.

Crossteaser
2.7*1011 positions
[Crossteaser home page]

Inversion

Mad Marbles

Magic Jack

Tumbler - van Deventer

Pionir Cube

Panex
Panex Puzzle resources page at Baxterweb
Play a level-4 version online at cheesygames.com.

? (Hungarian barrel)

Diamond Bob's Billiards Eight Ball, and Diamond Bob's Diamond 8

Rubik's Brain Racker

Bolaris
Designed by Hannu Hjerppe of Finland - website at www.bolaris.fi. Purchased at IPP28 in Prague.

The Bloxbox is notable since the design by Piet Hein is one of the first examples of sliding cubes in a cube. (The first U.S. patent, 416344, for a puzzle like this was awarded to Charles Rice in 1889.)

Cubedron and Cybedron
Pantazis Houlis at Mindstrat Puzzles has invented a series of what he calls "Gravity Puzzles." These are edge-matching puzzles encloszed in transparent spheres, where the pieces must be tilted into position so that patterns along the edges match, and a piece flips as it moves from one position to another.
Movable Gap, Movable Frame

Mind Twister aka Wisdom Ball
Yang Ju-Hsun
1 June 1993
1.7*1075 positions
Jaap's page

Saturn - LD Belgium
white and black versions

Tomy Great Gears
1.46*1020 positions
Jaap's page

This is called Entrapment. There are also some newer "clones" available. The clear plastic on the old ones is yellowed with age.

Atomic Chaos
Christoph Hausammann
2.1*1012 positions
Jaap's page

Pakovalec
aka Xylinder
1.3*1010 positions
Jaap's page

Missing Link
and the rarer Limited Edition
Marvin Glass & Associates
8.2*1010 positions

Whip-it
5.7*108 positions (for the 3)
Jaap's page

Bola RUVI (Whip-it Ball)

Ivory Tower and Babylon Tower
both 6 rows x 6 cols
1.9*1040 positions
Jaap's page

Varikon
4x4, 5x4 and 7x7
1.4*1014 positions
Jaap's page

Backspin
and a clone by Jaru
Ferdinand Lammertink
6.4*1028 positions
Jaap's page

Tomy and Milton Bradley Rack 'Em Up
Mizunuma Masanori and Watanabe Hiroyuki 1984
6.3*107 positions

Tomy Row By Row
Mizunuma Masanori
and Watanabe Hiroyuki
13 Nov 1984
2.8*1031 positions
Jaap's page

SpongeBob Puzzlepants
10,080 positions

Russian Flower

Touchdown

Calendar/Bank

Da Vinci's Mona Lisa Codebreaker


Twisted Mind - another version, using numbers, and with a transparent case.


Twist O Mania


Heartache - Kohner

Double Sliding - Dario Uri
No Gap, Rigid Frame (Interlocking Orbits)

Equator, and Hungarian Globe
1.1*1025 positions
Jaap's page


Hungarian Rings
Endre Pap
Also pictured - vintage cardboard/wood version Race War Puzzle Between Gold & Silver (I don't have). See U.S. Patent 507215 - Churchill 1893.
7.5*1019 positions
Jaap's page

Magic 8

Rubik's Rings
1.9*1014 positions
Jaap's page
a source

Circle Puzzle
369,600
[Jaap's page]

Rotascope
Raoul Henrique Raba 1982
9.1*107 positions
I obtained this Rotascope which is a souvenir of the sixth IPP at Jerry Slocum's house. The front contains invitation text and Jerry's home address and phone number, which I don't want to display here. This is a picture of the back - not very puzzling without a pattern to scramble.


Tsukuda Magic Puzzle
(Turnstile)
Douglas Engel
6.3*109 positions
Jaap's page


Lotica


Turn Push

Whirligig

Mad Triad
3.1*1045
(symbols matter)
Jaap's Page

Handy Mad Triad
8.3*1023 positions
Jaap's page

Rubik's Shells
4.7*1014 positions
Jaap's page

Cmetrick Too
There are colored disks riding in "craters" in spheres embedded in the frame. The spheres rotate and can exchange disks.

Cmetrick Too Hard
In this more difficult version, the centers of the disks are colored, too.
No Gap, Movable Frame

Topspin
Ferdinand Lammertink
2.4*1018 positions
Jaap's page

Trillion - red, black
Gunpei Yokoi
1.0*109 positions
Jaap's page

Nintendo Ten Billion Barrel
and Club Nintendo Star Barrel
Gunpei Yokoi
2.7*1014 positions
Solution site here.

I have seen this design from several places. I believe it has been called "Sortospherical."

The Orb[-it]
Christopher C. Wiggs
and Christopher J. Taylor
7.4*1028 positions
Jaap's page

Astrolabacus
John D. Harris
Pat. 8 Jul 1997
3.6*1016 positions
Jaap's page


Port to Port
Triple Cross
Ferdinand Lammertink
Pat. Aug 6 1996
5.9*109 positions
Jaap's page

Gripple
Murray J. Gould, patented 5 April 1988
2.0*1013 positions
Jaap's page

Russian Gripple

Magic Sphere

Rotos
Jaap's page

Magic Cross (Zauberkreuz)

Flip Side - Thinkfun

Swissmad
369,600
[Jaap's page]

Tsukuda's Square / "it"

Rubik's Fifteen

Binary Bisect 5 - Doug Engel

Palette 7 - Doug Engel

Elemental: Neon (aka Biohazard) #051, designed and made by David Litwin

Uriblock
(A custom version purchased at IPP28 in Prague.)
 
Tri-Trick
 
Overlapping Plates

Mind Lock

3-Level Puzzle
Dollar Tree

Jushbox


Here are some interesting sites: