RPG Game System

I roll for game development

The system of the RPG is the rules or the game mechanics use to determinate the outcome in the game. For a CRPG the player skill often also effect the outcome.

System origin

Your can use a existing system from a pen and paper role playing game, use a existing system from a CRPG or make your own.

Pen and Paper Systems

There exist many role playing game systems made for classic role playing games. Examples of systems are GURPS or D20. Most of these existing systems demand some form of license for them to be used. So it makes the most sense to use one of these if one is making a licenced product for the world where they players would expect the system to be used.

CRPG System

One example of a custom system is Fallout with SPECIAL.

Roll your own

The cool way :).

Character Skill vs Player Skill

Class/Level Vs Skill

There are two main ways to setup the character development in a system, skill based and class based.

Skill based: In a skill based system there is a pool of available skill's and as the the player progress with the character he is free to pick and choose skills as he feels like.

+ Choice: Possible to select any character that you wish to play.

- Skill combination imbalance:

- Skill Specialization Imbalance:

- To much choice:

- Stand Alone Complex

- Most skills seldom used

    • Ultima Games: At start of game select a Profession that influence the start abilities and items but it does not limit the choices later on.

    • Skyrim:

    • Morrowind/Oblivion: The selection of class gives some extra ability points and the Custom Class Skills select will increase more rapidly than other skills.

    • System Shock 2: One select career at start and it select the start skills but it does not limit further choices.

Class based: In a class based system there is a set number of classes to pick from and the class selected by the player limits what skills he can progress in.

+ Easy player introduction: A class-based system breaks the options into easy to understand categories for new players of the game.

+ Focused roles: Each class can have it's own role and will be good at his specialty.

+ Ding:

+ No unplayable builds: With classes it is easier to make sure that no build of characters turn out overpowered or broken.

+ Simpler game balance: There are fewer options so it is more easy to balance. Eight classes is more easy to handle then 80 skills where the player can take any of them.


One way to categorize characters is by the way they will be played.


For a online game the characters roll in combat is important. Tank/Healer/DPS is a common way to summarize the role of a

character. This often maps directly to the character classes in a online game.


Is a character that soak up damage in combat. The character has more hit points and better armor then other so he can get hit a lot without dying. Ex is a warrior.


The healer keeps the other alive and make sure they are stocked with power-up spells that make them survive longer or make more damage. Ex is priest.


Stands for Damage Per Second and it a character that can damage the enemy fast and kill them. Ex is mage.




The group of data that describe a character in a rpg is called the Statistic or stats. Normally some form of integer. Some common categories exist but it varies greatly between different systems. Other common names for each category is also given. Derived statistics are stats that depends on other statistics. For example the hit points of a character can depend on the strength and stamina.

Attributes (Abilities)

The core inbred abilities. Examples of ones used are Strength, Agility and Intelligence. Some games system keep them constant, other allow temporary affects to modify them and other system makes it possible to raise them as the player level up.

    • D20: Strength, Dexterity, Constitution, Intelligence, Wisdom and Charisma.

    • SPECIAL: Strength, Perception, Endurance, Charisma, Intelligence, Agility, and Luck.

    • Ars Magica: Intelligence, Perception, Strength, Stamina, Presence, Communication, Dexterity and Quickness.

    • Ultima Games: Strength, Dexterity and Intelligence.

    • World Of Warcraft: strength, agility, stamina, intellect, spirit

    • Titan Quest: Health, Energy, Strength, Dexterity, Intelligence

    • Skyrim: Health, Magicka and Stamina

    • Morrowind/Oblivion: Agility, Endurance, Intelligence, Luck, Personality, Speed, Strength and Willpower.

    • System Shock 2: Strength, Endurance, Psionics, Agility and Cyber Affinity.


Derived statistics are stats that depends on other statistics. For example the hit points of a character can depend on the strength and stamina.

    • D20: Hit points, Armor class, Initiative, Attack bonus, Saving Throws (Fortitude, Reflex and Will)

    • SPECIAL: Action Points, Carry weight, Critical Chance, Hit Points.

    • Ultima Games: Hits, Mana, carrying weight.

    • World Of Warcraft:

    • Morrowind/Oblivion: Health, Magicka, Fatigue and Encumbrance

Skills (proficiencies, abilities, talents)

A skills is a trained ability that the character can perform and each time it is performed there is a certain chance that it succeeds. The better at the skills the bigger the chance for success. For example a Pistol skill handle the chance for all action the character takes with any sort of pistol. Some skills can not be performed at all unless the character has some skill points in it.

Feat (Perk, power)

This is something the character can do but it is a on-or-off quality to it. Unlike a skill it is not possible to get better using it.

Virtues & Flaws (Advantages/merits/edges & disadvantages/flaws/hindrances )


The spices the creature is, like dwarf, elf or human. For some reason it is called race in fantasy and RPG settings. Race often add extra bonus to attributes or skills. So a dwarf is on average stronger then a human.


The sex of a character.


A role or archetype the character is. Ex is a warrior or a mage.

    • D20: Barbarian, Bard, Cleric, Druid, Fighter, Monk, Paladin, Ranger, Rogue, Sorcerers & Wizards

    • World Of Warcraft: Warrior, Paladin, Hunter, Rogue, Priest, Death Knight, Shaman, Mage, Warlock, Monk, Druid, Demon Hunter.

    • Titan Quest: Storm, Defense, Nature, Hunting, Rogue, Dream, Spirit, Warfare and Earth.

    • System Shock 2: Marines, Navy and O.S.A


The level of a character is how powerful it is. A level 20 character is more powerful then a level 10 character. When you hit a new level you often get to improve skills and other stats.


The system that handles how the player gets better. Can often be sorted into Skill or Class Based. In a class based system you gain level in your class and that limit what skill you can progress or gain. In a skill based system you gain experience in each skill and you can train the ones you like. Hybrids system is common also. Class based system works well in MMO's or games where you control a group of characters. It makes it easy for the players or player to plan it's group and less things to balance against each other. Skill based works well in single player where the player has a lone character and time to focus on each option.


A system to track progress. You can experience doing quests or killing things and when you get enough experience you gain a level.