Ways is a mechanism that avoids paylines. Instead, it is the number of positions on each reel multiplied by each other.
Traditional fruit machines with 3 reels have 1, 3 or 5 paylines. I do however remember a Bar-X variant, standard 3 by 3 layout to have ways, so it was 3x3x3 to give 27 ways.
5-reeler slots begun their lives with an odd number of lines, usually 9 or 15 lines. Later slots had rounded amounts like 10, 20 or 40 lines.
The first slot I saw to have ways was about 10 years ago, certainly no later than 2009. It was called Treasures of Troy with 4x4x4x4x4 to give 1024 ways. The feature was triggered by 2 scatters in the middle reel for 10 spins if memory serves and 3 scatters gave 15 spins. I’m not sure who made it but I think it had the same interface and sound effects as Super Hoot Loot and Dungeons & Dragons.