The format exists because pictures do not travel well
A Life pattern is a grid, but a screenshot is a poor way to share it. RLE stores the same pattern as compact text. That makes it easy to paste into tools, archive in catalogues, and attach to forum posts.
The header gives the width and height, often with a rule string such as B3/S23. The body uses counts plus tags: b for dead cells, o for live cells, $ for line breaks, and ! for the end.
A glider fits in one short line
The LifeWiki RLE page gives a glider as bo$2bo$3o!. Read it row by row: one live cell after one dead cell, then two dead cells and one live cell, then three live cells.
Once that grammar clicks, RLE stops looking like a code dump. It becomes a compressed drawing.
Why this site should support it later
RLE import and export would let users move between this lab, LifeWiki, Golly, and other viewers without redrawing patterns by hand.
It also creates a clean publishing workflow. An article can explain a pattern, the simulator can load it, and the source RLE can remain available for readers who want to reproduce the exact starting state.
Working takeaway
RLE is the next practical bridge between a beginner-friendly lab and the larger Life community. It should be treated as a product feature, not only a file format.