Posted by: EvilNando | January 20, 2009

RPG Mechanics part I


Right now Im working in creating a mathematical model for representing the rules for the RPG game.

At first I thought to simply rip off the DnD ruleset and apply it to the game, but after a second thought I realized that this in the end will hurt the development process.

So what Im doing right now is to come with the initial draft for the mechanics.

My plan is to create a series of formulas, this way you can input the level and the class and the formulas will give you all of the current base statistics, since the derived statistics (see combat pdf) are all calculated from the basic ones I can quickly create the stats for a single character in the game.

Here is my initial creation process:

define your class favored and secondary attributes

  1. Assign a value from 10 to 1 to each stats: start by assigning 10 to your class favored stats , 8 to the secondary stat and so on. We will call this value as the Priority Factor or PF
  2. Apply the formula: PF * LVL + 2 * (MOD(LVL;3)) + 10 + LVL

With this I can obtain some nice curves and Im also able to select which classes favor each basic statistics:

Heres an example of creating a class that favors Str as a primary attribute, we will call it the Warrior Class:


  • Str = 10
  • Con = 8
  • Dex = 6
  • Int = 1
  • Wis = 3
  • Cha = 4

Note: Luck has the same progression for all classes; Here is the formula:


Here is the chart for the warrior class from level 1 to 20, I think it looks ok.



Now its time for some testing. Ill be writing a program which will evaluate a fight between 2 lvl1 warriors armed with basic equiment (longsword and chainmail).

The program will iterate about a million times and at the end will return the average hits that it took to down one of the warriors.

This way I can tweak the stats so each fight is short enough to keep players from getting bored.

Next update I will post the whole evaluation results.


Thanks for reading



  1. Why did you choose to have luck run the same for everyone, and in what situations will luck be used? I have more questions, but lets start here 🙂

  2. Luck is the coeficient that it is used to check if the attacker has scored a critical hit

    a critical hit doubles the inflicted damage (before the defender reductions) so if this is managed poorly critical hits can break the game

    it will be posible to raise luck by using spells or wearing items.

    luck is explained in more detail in the combat pdf document (see previous post)

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s


%d bloggers like this: