# OCA Discovery of the Year

The **OCA Discovery of the Year**^{[note 1]} (**OCADOTY**) competition is held each year on the ConwayLife.com forums as a counterpart to Pattern of the Year dedicated to rules other than Conway's Game of Life. Users are invited to submit interesting and noteworthy patterns, rules, families of rules, or projects relating to other cellular automata, their own or others'; following discussion, a final list is then curated, and a public vote held. All entries must have been found during the year in question.

## Results by year

### 2021

The OCA Discovery of the Year competition for 2021 was organized by Saka and Cyclotrons. Voting will end on September 1, 2022.

Final rank | Stars | Pattern/Discovery | Author(s) | Link(s) |
---|---|---|---|---|

Description | ||||

1 | 42 | INT Langton's Ant Simulator (B3-cjkq4knqy5cnr7/S02-cn3-ak4eiq5kq6e7e) | Silversmith | [1] |

A small INT Langton's Ant Simulator in INT rule B3-cjkq4knqy5cnr7/S02-cn3-ak4eiq5kq6e7e | ||||

2 | 34 | jellyfishless gun in B36/S245 | Luka Okanishi | [2] |

jellyfishless gun in Logarithmic replicator rule, analogously for the gliderless constructions in CGoL | ||||

=3 | 33 | a (2,1)c/4 in B256/S4568 | May13 | [3] |

Spaceship moving at fast oblique speed (2,1)c/4 | ||||

=3 | 33 | several patterns with unusual growth rate | AforAmpere and Connor Steppie | [4] |

several patterns with unusual growth rate | ||||

5 | 28 | wwei's quad-glider rule (B3-ky4jy5cr/S2-in3-aeky4cnrt5a6ekn) | wwei | [5] |

wwei's quad-glider rule (B3-ky4jy5cr/S2-in3-aeky4cnrt5a6ekn) | ||||

6 | 27 | a number of new OT rule being proved to be Turing-complete | many | [6] |

a number of new OT rule being proved to be Turing-complete | ||||

=7 | 25 | a fast W110 replicator | AforAmpere | [7] |

T-tetromino as a fast W110 replicator - self-supporting unit cell between rules B2ai3aeir4r5ei/S3e5e6i and B2-c34-i56-i78/S2-ai3-i4-e5678 | ||||

=7 | 25 | May13's Shipworld (B3acijy4-a5cjkr6-in78/S2n3-c4-aijz5-jy6-k) Spaceships | May13 and AforAmpere | [8] |

May13's Shipworld (B3acijy4-a5cjkr6-in78/S2n3-c4-aijz5-jy6-k) Spaceships | ||||

9 | 23 | new figseed records | many | [9] |

new figseed records | ||||

10 | 22 | a number of new highest period spaceships | many | [10] |

a number of new highest period small alien spaceships | ||||

11 | 20 | various LtL spaceships found by cfind | lemon41625 | [11] |

various Larger than Life spaceships found using cfind | ||||

12 | 19 | new OT hexagonal spaceships | creeperman7002 | [12] |

new spaceships in outer-totalistic rules with hexagonal neighbourhood | ||||

13 | 16 | a number of new symbiosis discoveries | many | [13] |

a number of new symbiosis discoveries | ||||

14 | 11 | LeapLife billiard tables | wwei | [14] |

LeapLife billiard table oscillators |

### 2020

The OCA Discovery of the Year competition for 2020 was organized by Peter Naszvadi and bubblegum.

Final rank | Stars | Pattern/Discovery | Author(s) | Link(s) |
---|---|---|---|---|

Description | ||||

1 | 45 | Day and Night knightships incl. a growing one | AforAmpere and Adam P. Goucher | [15] [16] [17] [18] [19] |

Various knightships in B3678/S34678 (Day and Night), including a growing knightship | ||||

2 | 44 | Small natural replicator simulating W110 | Arie Paap | [20] |

Replicator that follows the computationally universal 1D rule W110 | ||||

3 | 43 | Tiny adjustable ships/oscillators | Arie Paap and Oscar Cunningham | [21] [22] [23] |

Adjustable ships/oscillators: mobile ship tracks (diagonal ship bouncing between and slowing down two orthogonal ships), also the first relativistic adjustables; 3-cell adjustable spaceship family with infinite speeds and a rule family with 12 members supporting 3-cell adjustable oscillators covering all periods, by Oscar Cunningham | ||||

4 | 41 | Speed Orthogonoids and Geminoids | cvojan | [24] |

304c/11272 Orthogonoid and (700,100)c/72300 Geminoid in B2c3aeij4krtyz5cij6-ak7/S2-ik3-aek4aeiknw5a6ikn7 (Tubular) | ||||

5 | 40 | Wire-like rule 1e2-a3-cij4kaijrtz5cnrq/2ce3aejnr4aj5y6a/3 | silversmith | [25] |

1e2-a3-cij4kaijrtz5cnrq/2ce3aejnr4aj5y6a/3 (A Wire-Like World), a universal Generations wiring rule with complex dynamic circuitry and construction capabilities | ||||

=6 | 39 | Oblique (421,1)c/867 ship | AforAmpere | [26] |

Spaceship moving at (421,1)c/867 | ||||

=6 | 39 | LFoD O(t^(3/2)) growth construction | FWKnightship and praosylen | [27] |

Constructed pattern in B2/S0 (Live Free or Die) that grows with a complexity of O(t^(3/2)) | ||||

8 | 38 | Various LeapLife discoveries | Hunting | [28] (a compilation of known technology can be found at [29]) |

Meta-discovery: An attempt to reproduce the development of CGoL - and see how state of art tools and blueprints could accelerate this process with much success. | ||||

9 | 37 | Various W110 unit cell constructions | Naszvadi, FWKnightship, Layz Boi and GUYTU6J | [30] [31] [32] [33] [34] [35] [36] [37] |

Various W110 generalized unit cells, rakes and (noncompact) stripes in Day & Night, Morley, Logarithmic replicator rule, B368/S12578, Live Free or Die, Seeds, Life without death, DotLife, a TC 4-state von Neumann rule, 14-state OT hexagonal rule with 2×2 CGoL unit cell and a 4-state hexagonal rule directly simulating CGoL | ||||

10 | 36 | B378/S23 first glider gun | Matthias Merzenich, Naszvadi and Paul Tooke | [38] |

Márta guns, the first guns in B378/S23 | ||||

=11 | 35 | Natural adjustable ships | Saka | [39] |

Adjustable-speed spaceships to have been found naturally rather than constructed, with unusual complex mechanism for adjustability. A Diamoeba-like IOT rule: B2ci3-i4cit5-i6-i78/S3a4t5678 | ||||

=11 | 35 | First Unit Cell's visualisation rule | Naszvadi | [40] |

Visualisation of CGoL patterns in the first ever constucted p5760 unit cell grid | ||||

=11 | 35 | Failed replicator in OT rule B378/S2458 | LaundryPizza03 | [41] |

B378/S2458, a new gem of an OT rule with a failed 1D replicator | ||||

=11 | 35 | Box-pushing spaceships | Saka | [42] |

Various spaceships including boxes with smaller spaceships pushing them from the inside, right triangles and crosses | ||||

=15 | 34 | Various Symbiosis discoveries and constructions | many | Too many to list; the first post in the Symbiosis thread in 2020 can be found at [43] |

New developments in Symbiosis, including a vast array of oscillators and guns, lightspeed signal circuitry and a unique MSM breeder. | ||||

=15 | 34 | Various oscillators and spaceships in HROT rules | lemon41625, Saka, Chris Rowett and Hunting | [44] |

Oscillators and spaceships in HROT rules: circular chequerboards fighting for territory, and rocket rules in the cross neighbourhood | ||||

17 | 33 | Spaceship discovery progress in Life-like von Neumann rules | Naszvadi and praosylen | [45] |

Various spaceships and replicators in R1 OT B0 VN rules | ||||

18 | 32 | HROT Almostlife discoveries and W110 constructions | lemon41625 and FWKnightship | [46] |

R2,C2,S6-11,B9-11,NW0010003330130310333000100 (AlmostLife), a HROT rule very close to Life resembling an INT rule, with first ever constructed HROT unit cell simulating W110 by FWKnightship | ||||

19 | 30 | B36/S245-alike logreplicator | AforAmpere | [47] |

Replicator emulating the B36/S245 logarithmic replicator | ||||

20 | 29 | Binary counter-stretcher-lograke-ship | Naszvadi | [48] |

Binary counter one-ended wavestretcher/logarithmically-growing spaceship | ||||

21 | 25 | Crystal Chaos HROT rule | Connor Steppie | [49] |

R2,C0,S4-7,9-11,B4,NB (Crystal Chaos), a dynamic HROT rule with a hidden crystal structure that allows for fragile explosions |

### 2019

The OCA Discovery of the Year competition for 2019 was organized by testitemqlstudop and bubblegum.

Final rank | Stars | Pattern | Author | Link(s) |
---|---|---|---|---|

Description | ||||

=1 | 37 | Dominoplex Orthogonoid | 2718281828 | [50] |

Orthogonoid spaceship in rule B2cen3ek4ejkwz5-ein6an7e8/S12an3-eijq4enrty5e6k. | ||||

=1 | 37 | Orthogonoid | AforAmpere | [51] |

Speed orthogonoid spaceship in rule B2ein3cijn4cnrwy5cnq6e/S1c2-ai3acny4anqy5c6ek8. | ||||

3 | 33 | Snowflakes' pseudo-Orthogonoid | Goldtiger997, et al. (2718281828, dani, toroidalet, BlinkerSpawn, etc.) | [52] |

A pseudo-orthogonoid, a self-constructing puffer. | ||||

4 | 26 | RROs | 2718281828 and AforAmpere | [53] |

massive reflectorless rotating oscillators. | ||||

5 | 25 | 3S1CShip8 and its c/2^6911+6913 one-cell ship | fluffykitty | [54] |

3S1CShip8 and its c/2^6911+6913 one-cell ship. | ||||

6 | 24 | Non-explosive B1e rules | toroidalet, Saka, testitemqlstudop, Arie Paap, praosylen, et al. | [55] |

Non-explosive B1e rules. | ||||

7 | 23 | B2a/S circuitry | toroidalet | [56] |

Signal logic circuitry with replicator streams | ||||

8 | 22 | Additions to the 5S project | Arie Paap, et al. | [57] |

Additions to the 5S project, especially these ones: (176,1)c/440, 108c/37886 diagonal, (98,97)c/4312 | ||||

9 | 21 | GUYTU6J's OCA discoveries | GUYTU6J | [58] [59] [60] [61] |

Triangular and ruler replicator + SMOS, 2D replicator with beautiful fractal, 2D replicator firing gliders and 10c/20s, Bizarre rake-plicator | ||||

10 | 20 | Hactar's 2x2 p2 metacells | HactarCE | [62] |

Hactar's 2x2 p2 metacells simulating outer-totalistic life-like rules. | ||||

11 | 18 | Omosso's pair-interaction ships | 77topaz, et al. | [63] |

Omosso's pair-interaction ships with very high periods. | ||||

=12 | 17 | Mahler-rep | Letters | [64] |

Mahler-rep, a modification of Devore which allows for smaller replicators and computers. | ||||

=12 | 17 | Rule X3VI | Rhombic, testitemqlstudop, et al. | [65] |

The first INT rule to reach 1T objects in C1 on Catagolue. | ||||

14 | 16 | Rule 110 in Codd | Naszvadi | [66] [67] |

Usual W110 unit cell that proves Turing-completeness of a classic 8-state vN rule by E.F. Codd. | ||||

15 | 15 | ZombieLife | 77topaz, Moosey, dani, Dave Greene, et al. | [68] |

A rule with its enormous natural spaceships. |

### 2018

The nominations for the 2018 competition were organized by Rhombic, and the voting by 77topaz. Users were able to vote on as many entries as they wished, awarding up to three stars to each one.

Final rank | Stars | Pattern | Author | Link(s) |
---|---|---|---|---|

Description | ||||

1 | 38 | Adjustable slope spaceships | AforAmpere | [69] |

Spaceships which can be adjustable to travel at any integer slope. | ||||

2 | 24 | bf esolang simulator | M.I. Wright | [70] |

A cellular automaton simulating the bf programming language. | ||||

=3 | 23 | ATPP | dani | [71] |

A rule containing many spaceships based on failed replicators as well as several actual replicators based on it. | ||||

=3 | 23 | Exponentially long-lasting methuselahs | toroidalet | [72] |

Various fuse-based methuselahs, one of which has an estimated lifespan of 2^{2^50} generations.
| ||||

5 | 22 | Smallest Oscillators Supporting Specific Periods | Oscar Cunningham | [73] |

Examples of two-cell oscillators for every period up to 102. | ||||

6 | 21 | 8c/9 orthogonal spaceship | AforAmpere | [74] |

The fastest known sub-lightspeed spaceship in an isotropic non-totalistic rule without B0. | ||||

7 | 20 | Suns | Goldtiger997 | [75] |

A rule containing a high-period oscillator which can be hassled at various other periods. | ||||

8 | 18 | JvN29 loop-based replicator | fluffykitty, Redstoneboi | [76] |

A replicator in von Neumann's original cellular automaton. | ||||

=9 | 17 | Omosso | Saka | [77] |

A rule containing high-period spaceships, a natural RRO, and OMOSes of various periods, hence its name. | ||||

=9 | 17 | Rule 110 unit cells in various rules | Peter Naszvadi, Luka Okanishi, LaundryPizza03 | [78] [79] [80] [81] |

Proofs of Turing-completeness for rules including but not limited to HighLife, DryLife, and LowDeath. | ||||

11 | 16 | tlife puffer | dani, Luka Okanishi | [82] [83] |

An 8c/282 orthogonal puffer, and a spaceship based on it. | ||||

=12 | 15 | Hype | FlameandFury | [84] |

A rule with a wide variety of high-period oscillators which has also been proven omniperiodic. | ||||

=12 | 15 | Hive | dani | [85] |

A rule with a failed replicator from which various high-period and unusual-speed spaceships have been constructed. | ||||

=14 | 14 | Record-slowest spaceships | AforAmpere | [86] |

A rule table supporting spaceships based on Knuth's up-arrow notation, allowing for unimaginably slow speeds. | ||||

=14 | 14 | Emitters | dani | [87] |

A rule with many high-period oscillators (similar to Hype) but also a small spacefiller, a replicator, and several guns. | ||||

16 | 13 | Other adjustable spaceships | Luka Okanishi, Connor Steppie, Arie Paap, 2718281828, AforAmpere | [88] |

17 | 11 | Other RROs | 2718281828, et al. | [89] |

18 | 10 | Arrow | 77topaz | [90] |

A rule with adjustable rakes and many known reactions based on them. |

### 2017

The 2017 competition was organized by Rhombic. Users were able to vote on as many entries as they wished, awarding up to three stars to each one.

Final rank | Stars | Pattern | Author | Link(s) |
---|---|---|---|---|

Description | ||||

1 | 25 | Orthogonal adjustable spaceships | praosylen, Luka Okanishi | [91] [92] |

Two rules allowing for the trivial construction of infinitely many odd and even-period spaceships respectively. | ||||

2 | 18 | 5s project | dani, et al. | [93] |

A collection of the smallest known spaceships of every speed among the isotropic non-totalistic rulespace. | ||||

=3 | 15 | SMOSMOS | Saka, et al. | [94] |

The first known spaceships made of SMOSes, with various examples posted. | ||||

=3 | 15 | Movostill 3 | dani | [95] |

A rule with various elementary spaceships and guns as well as construction potential. | ||||

=3 | 15 | HighLife replicator spaceships | Luka Okanishi | [96] [97] [98] |

Replicator-based spaceships traveling at speeds of c/18, c/12, and c/30 diagonal respectively. | ||||

=6 | 14 | tDryLife pondlayer-based spaceship | Luka Okanishi | [99] |

An engineered spaceship based on a high-period pond puffer. | ||||

=6 | 14 | One-cell universal constructor | blah | [100] |

A method of producing arbitrary complex patterns from a single cell using rule tables. | ||||

8 | 12 | Snowflakes | BlinkerSpawn, dani | [101] |

A rule with construction potential despite its differences from Conway's Game of Life. | ||||

9 | 11 | Rule 110 unit cells in various rules | Peter Naszvadi | [102] [103] [104] [105] |

Proofs of Turing-completeness for certain Life-like rules including but not limited to Pedestrian Life, EightLife, and HoneyLife. | ||||

=10 | 9 | Spaceship-bouncing-off-object adjustable spaceships | Connor Steppie | [106] |

=10 | 9 | Extremely slow spaceships | BlinkerSpawn, et al. | [107] |

The design of spaceships with excruciatingly slow speeds using different approaches | ||||

12 | 7 | Slope-73 spaceship | AforAmpere | [108] |

A (73,1)c/160 spaceship, at the time the oblique spaceship with the steepest known slope. | ||||

13 | 6 | Larger than Life developments | Saka, Connor Steppie, et al. | [109] [110] [111] |

A collective entry for various discoveries within the Larger than Life rulespace. |

## Notes

- ↑ "OCA" is an acronym for "other cellular automata."