First let's talk about Experience gain, while it may be detrimental to growth as my first book, I'm gonna use something that may or may not work:
Experience Rates + Requirements
1 - 10 = 100 x (level)
11 - 50 = 1000 x (level)
51 - 100 = 10000 x (level)
101 - 175 = 100000 x (level)
176 - 300 = 1mil x (level)
301 - 500 = 10mil x (level)
501 = 100mil^2
Experience Drop Rates from Level + Level Difference
Mobs of a lower level = 10 x (level % (player's level)) (hard decrease)
People of a lower level = 100 x (level % (player's level))
Mobs of a higher level = 10 x (level x (player's level))
People of a higher level = 100 x (level x (player's level))
Now, onto calculating what each stat does and how it affects our story:
Attack = 1 point = 1 dmg
Magic Attack = 1 point = 2 dmg
Defense = 1 point = -0.5 dmg taken
Vitality = 1 point = 10hp + 10 Mp
Agility = 1 point = 1 movement speed + 0.01% chance to dodge
Mana = Determined by how much mana each spell costs
Charisma = 1 points = .25% easier to persuade someone of the same level
- for lower level + .5% per level above
- higher level -.5% per level lower
Movement Speed = 1 point = .45 m/s or 1 mph
Charisma being gained as the character becomes more decorated in titles/achievements