On the MSN Gaming Zone, I downloaded a map editing tool called QARK. I figured out on Q2DM1 (The Edge), that there was a game bug involving hitting the space-key (jump) multiple times on different surfaces, would cause you to 'double jump, triple jump' and so forth. It was the most obvious in attempting to get the ultra-health pack in the corner of the main room where you'd also grab the chaingun and combat armor. I implemented this on the very first map I ever created called q2dm_jump1. Little did I know what I would start.
Someone followed after my heart in Counter-Strike: Source and through some sort of fluke figured out that holding down walk on a slope causes you to slide on it. Surf anyone?