Hello CipsoftStinks,
It means Artificial Intelligence, it applies to how monsters behaved themselves back in 2004~2006 (Movement, AttackSpeed depending on Distance if the monster is ranged or not, an actual calculation going on with monster's Defense and Armor values instead of the -let's put it this way- really bad implemented original tfs formula, which takes only the defense value from the .xml and set it to maxDefense then divides maxDefense by 2 and that'd be minDefense, a number between the range of minDefense and maxDefense is what the monster will actually defend, which is totally wrong.
I sat down with a few people here and there and managed to create this code for 0.4, which runs on my server. It isn't way too complicated but it's rather long (over 2k lines for the movements and combat, some 100 lines for the new defense formula).
I also have got so far and converted some dumps from the real leaked binary (from cipsoft) and managed to get some other functions from real tibia running on TFS like the spawnTime being dynamic and modified depending on the number of players on the server.
Best Wishes,
Okke