* Leveling up costs gold. It's not cheap.
* You cannot level beyond the maximum level (40).
* For each levelup, you have a fixed number of points to spend on attributes and skills. Attribute points can be spent on any attribute, regardless of what skills. I.e. no power leveling.
* All of this is very configurable. You can make it quite easy or quite difficult as you prefer.
For a list of other leveling systems, see http://www.gamesas.com/bgsforums/index.php?showtopic=790175 (section 4). (I'm not sure where this fits in this scheme, other than that it's pretty much the opposite of natural grow type systems.)
Links:
* http://wrye.ufrealms.net/#OblivionMods or http://tesnexus.com/downloads/file.php?id=23322
* http://wrye.ufrealms.net/Wrye%20Leveling.html
Screenshots:
* http://wrye.ufrealms.net/images/Leveling_01.jpg: Shows all attributes with current values and distributed attribute points. Clicking on an attribute takes you to sub-menu...
* http://wrye.ufrealms.net/images/Leveling_02.jpg: Shows attribute and related skills with current values and points assigned to them. Clicking on attribute/skill adds a point. Shift-clicking removes a point. Any single attribute can be increased by up to 5 points, any single skill by up to 10 points. (Note: These limits, like most of the limits are configurable.)
* http://wrye.ufrealms.net/images/Leveling_03.jpg: Can config cost, round limits, final limits.
* http://wrye.ufrealms.net/images/Leveling_04.jpg: Config points available, max gain per attribute/skill, min days between levelups. (Note: These are not the default settings.)