A rule table.
A repeatable experiment.

This lab compares exact Conway B3/S23 transitions with a fixed table recorded from the real TypeSafe Jev API. It is an independent experimental playground, not an engineering model or a general benchmark of Jev.

The recording

• Model: jev-1.13.0, recorded September 30, 2026.
• All 512 binary 3 × 3 neighborhoods, including the center.
• 18 control cases: center alive/dead × eight-neighbor counts 0–8.
• Raw grids: 231/512 correct. Counted controls: 18/18 correct.
• 17 successful provider requests. The browser replays their results without further provider calls.

The 18 control answers are expanded to a 512-entry table by each neighborhood’s center state and exact neighbor count. A count-based control is a simpler task; this comparison does not isolate the model’s internal mechanism.

Download the complete recording (JSON) ↓

Exact mechanics

The world is 64 × 40 cells. All cells update synchronously. A dead cell is born with exactly three live neighbors; a live cell survives with two or three. The 3 × 3 encoding is row-major with the top-left cell as the least significant bit and the center at bit 4. The center is excluded from the neighbor count.

Both worlds start with the same bitmap. Choose wrapping boundaries or a dead exterior. Seeded random grids are reproducible; the exported report includes the initial states, boundaries, table, generation and model metadata.

The glider observation

With the bundled raw table and wrapping edges, the built-in glider at generation 263 has 442 live cells, compared with five in exact Conway Life, with 441 different cell states. The one-click discovery replay computes this result locally. Rule-family repair experiments are in progress; the lab does not present those unfinished results as conclusions.

Read the original work

John Horton Conway created Life; Martin Gardner introduced it to a broad readership in 1970. Stephen Wolfram’s A New Kind of Science and work on minimal models of machine learning offer relevant context for exploring local rules and their consequences. Neither author nor TypeSafe endorses this project.

Take it apart with us

Join eR33t Gaming on Discord ↗ — an 18+ gaming community with room for curious experiments.