OpenTibia Sprite Pack (OTSP) uses different IDs for everything.
- default OTSP protocol is 10.41, make sure your engine is downgraded or that you change OTSP files protocol;
- different effects and IDs, you might want to change tons of stuff at const.h source file (here);
- maybe you would want to change effects name to reflect current ones, it would change how you make spells and monsters spells (here);
- CONST_ME_TELEPORT and other ones are used in a lot of places in the code, you might want to change that (here);
- you will need to change actions/movements/weapons for OTSP items ids;
- change Doors at global.lua (here);
- create totally new spells using OTSP effects;
- create totally new monsters using OTSP outfits;
- add the outfits to outfits.xml (here);
- add more details and custom information to our items.xml;
- make sure it search for otsp.spr and otsp.dat files instead of deafult ones (here);
- check starting outfit and starting items ids (we have outfits from 1-24, 17-21 better suited for players);
- ItemEditor: https://github.com/ottools/ItemEditor
- ObjectBuilder: https://github.com/ottools/ObjectBuilder