The Royal Scientific Society of Tibia (RSST) was a unique guild that wasn't centered around the idea of helping players avoid PKs, causing chaos in Tibia, or even to roleplay. Their goal was instead to create a deeper understanding of the mechanics of Tibia. Founded on October 16th, 1998, likely by Rabscuttle, they started right away in determining the formula for how exp and levels related to each other as it was unknown prior to this point (CIP didn't post the exp table that we have now).
Just 9 days after they cracked the exp code they went on to tackle other formulae such as how close quarters damage was determined. In their landmark document, cheekily called Dues ex Machina, they detailed the results of their hard work, creating Tibia's first skills calculator. Though not always accurate at higher skill levels, players still could use the rough numbers to plan what was needed for their next advance or budget money for improving their magic level, eliminating some of the mystery behind these common functions.
True to their format, they also engaged in semi roleplay, with sir martin I hosting the first Tibian lecture on "How to find out something about the close-combat fighting system?". The discussions here would create a logical approach to discovering other damage formulae like spell duration and the specifics of dealing and receiving damage. Players from this point on would look deeper into the mechanics of the game and provide tools to fellow players to improve their game experience.
One of the most important documents that remains of this guild is their work on the Beta 5 update test which gives us the only glimpse of what early test servers were like and the changes which occurred. The test phase for Beta 5 is interesting in that the recorded notes are taken from the long-lost forums. There is rich detail in what is recorded and interestingly it seems players were unclear what should be a feature or not, like what actually changed was not mentioned anywhere so they had go guess if it was a feature or not. Sadly no further updates from the RSST exist after this point so it is unclear why they vanish so suddenly.
https://web.archive.org/web/20010119084000fw_/http://homepages.go.com/~rsst1/bugtrap.htm