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High Level Summary of Game Mechanics

Here is a high level summary of the Atomic RPG System system. It is important to note that the Atomic RPG System is not just a rule set for an RPG. It is also storage, management, and a content generator for anything players can imagine. So besides the core RPG rule system, there is much more that helps players and GMs make RPG gaming easy. Roleplay your way with the Atomic RPG System!

The Atomic RPG System is primarily designed to be played as a tabletop RPG, but because it’s entirely web-based, it can also be played via chat or video conferencing.

The Atomic RPG System makes an effort to reduce everything a character can do into the smallest and easiest set of stats while still maintaining the ability to have powerful individual characters.

  • The core Atomic RPG System rule system uses a d20 (20 sided dice) to determine success or failure in an action. The higher the roll on a d20, the better.
  • Characters gain overall strength by gaining levels. Levels 1 through 20 are available.
  • The GM levels up the group together. The rate at which the group levels is up to the GM.
  • At each level, characters gain 1 Trait Point, 1 Specialty, and Increase 2 Skills.
    • Most game numbers use a Character Trait, a character’s level, and the Character’s Tier in calculations. Most numbers on a character sheet get better (go up) every level.
  • Character strength can be further enhanced with items.
  • Character strength can be further enhanced with Powers.
    • Powers equate to spells, abilities, or superpowers.
  • Character changes to any player choice is possible throughout the life of the character.

Character Archetypes (Classes or Paths)


Primary focus on combat abilities.


Primary focus on skills and party-aiding abilities.


Primary focus on magic or supernatural abilities.

Different Archetypes have access to different abilities. 

Define Character Further with Style and Focus

In the Atomic RPG System players can have their characters access more then just one Archetype abilities. You can choose to be more spread out but have more access to various abilities.


How strongly are you focusing on your primary Archetype?
Devoted (All Focus)
Focused (Most Focus)
Balanced (Some Focus)


How you are going to use your primary abilities?
Aggressor is aggressive
The best defense is a good offense. Grants bonuses to Attacks.
Protector is defensive
Defense first, attack if necessary. Grants bonuses to Defenses.
Neutral Depends on situation.
Grants bonuses to Skills.

Specialties Refine Character

Specialties are available every level. Specialties are designed to further enhance a character. They might be used to increase Hit Points, Skills, Defense, etc. There are hundreds of Specialties to choose from.

High Level Summary of Skills

Skills help characters accomplish non-combat related activities. Each skill has a base score that is the associated Trait. Characters can improve 2 skills per level. There are 9 Skills in the Atomic RPG System. These skills cover actions outside of Battle Time (and sometimes, within Battle Time). The better the number associated with the Skill, the better chance of success at a Skill check.

  • Athletics: (Body) Used for physical tasks.
  • Crafting: (Best) Used to create items.
  • Language: (NA) This skill is rarely rolled. Instead it grants additional Language for each time it is increased.
  • Nature: (Spirit) Used for natural animals and environments.
  • Perception: (Spirit) Used to detect something through a character’s senses.
  • Religion: (Mind) Used for religious and spiritual tasks.
  • Scholar: (Mind) Used for learned tasks.
  • Social: (Spirit) Used when interacting with others.
  • Subterfuge: (Spirit) Used when attempting to deceive, trick, or be underhanded.

Any particular skill check can only be done once. Players can aid each other. Players usually get to decide which of two skills to roll against to attempt a task, such as Athletics or Subterfuge to sneak around.

Powers define the awesome that is a character.

Powers are what other games may call spells, abilities, class or racial abilities. A player builds Powers by spending Power Points from a Power Point Pool. These Power Point Pools are derived from the character’s Focus, Level, related Trait, Specialties, and more.

Summary of Character Stats (Numbers)

  1. Level 1-20: Represents a character’s overall strength.
    • The group goes up a level all at the same time, not individually. The GM determines when characters will increase in level.
    • Character Tier is derived from the Characters Level. It is general strength class of a character. Tier 1 – 1st Level, Tier 2 – 5th Level, Tier 3 – 9th Level, Tier 4 – 13th Level, Tier 5 – 17th Level.
  2. TraitsBody/Mind/Spirit: Represent the core of a character. These Traits correspond to Combatant/Mystic/Generalist abilities respectively.  Traits affect almost everything on a character.
    • 12 Points are distributed between these 3 Traits at level 1. They must be 1 or higher. A character can increase 1 Trait each time they level.
  3. Hit Points: Represent a character’s willingness or ability to continue. Hit Points are usually lost when hit by a Power. Hit Points can be lost by many different means, not just physical damage.
    • Traits x Level x Character Tier + 20 Hit Points
  4. Defenses: Represent a character’s ability to resist offensive actions that would lower their resolve (Hit Points).
    • Trait + 10 Base | Each Defense (Combatant[Body], Generalist [Spirit], Mystic [Mind]).
  5. Attacks: Represent a character’s ability to cause harm to another character. (Hit Points, Penalties, Movement, and more)
    • Trait Base | Each Attack Discipline (Combatant[Body], Generalist [Spirit], Mystic [Mind]).
  6. Healing: Represents a character’s ability to increase all the Hit Point Healing they cause. (Powers, Items, etc)
  7. Damage: Represents a character’s ability to increase all the Hit Point Damage they cause. (Powers, Items, etc)
  8. Skills: Represent a character’s ability to interact with the world.
    • Base Trait + Level Increases | Skill checks range from 10 to 100 more depending on the task at hand.
  9. Powers: Represent a character’s ability to affect one or more character’s stats.
    • Powers are adjudicated strictly by the effects of the Powers: Range, Target, Duration, and Effect.
    • Power can be anything a player can imagine: spell, sword swing, roundhouse kick, psionic attack, inspiring poem, noxious liquid, sweet treat, medication, stim packs, supernatural, super human, cyborg enhanced, etc. The name and description have no impact on the effect of the Power. Name and description are for roleplay only.
    • Characters have 2 or 3 groups of Powers, called Disciplines: Primary, Secondary, and sometimes Tertiary.
    • Characters have Power Points to use to create Powers for their characters in each Discipline.
    • Characters generally have 5 to 10 Powers total.
    • Characters will have 1 or 2 Powers that are At Will Powers. These are Powers that can never but expended.
    • All characters have access to 6 Combat Maneuver Powers. These include Basic Attack, Knock Around, Head Games, Exploit Weakness, Parley, Reckless Charge, and Tactical Retreat. They can be used At Will and never be expended.
    • All regular Character Powers can be used 1 time during Battle Time. They are usable again when if game play moves from Battle Time to Turn Time or Real TIme then back into Battle Time.

This might seem like a lot to wrap your head around.

However, it is less then most other games and is calculated automatically with our digital character sheet!

High Level Summary of Basic Gameplay

The purpose of the Atomic RPG System is to play a character in any fantasy setting. This character is usually joined by 3-5 others in a group. This group explores and solves problems in the fantasy setting. These are the player characters, or PCs.

There is a Gamemaster, or GM. The GM also plays the game, but the main job is to tell the story, or quest. Their job is also to moderate the players and to keep order in the game.

In the Atomic RPG System there are three game modes. Gameplay changes between these three game modes depending on the type of action that is happening in the story.

Real Time

Roleplay or story time. The PCs and GM act out the story outside of any actions that need rolls to resolve. This is a free form time when players do not have to take turns.

Turn Time

This is the main time during a game when Skills are used. Many challenges and other situations cause the PCs to roll Skill Checks to determine success. Players must begin to take turns at this point.

Battle Time

When any character or non-player character takes an offensive or harming action against another, the game moves to Battle Time. The players' actions are controlled by more rules.

The GM sets up the quest with the story, and the PCs act like their characters, make decisions as their character would, and should work together to resolve the conflict of the quest. The game moves through the various game modes depending on the action in the quest. The GM oversees what is happening but works with the players to tackle new issues and different ideas to solve the conflict of the game.

Characters are defeated when they drop below 0 Hit Points, are Held Captive, or otherwise fail the quest they were attempting.

Give it a try now. No account needed!

There are an infinite amount of possibilities when playing the Atomic RPG System. The Atomic RPG System is specifically designed and built with a fast and optimized rule set to allow both GMs and players the freedom and ease to create whatever they want.

If you have any questions or comments please post them on our message board. We are happy to answer them!

Create your own custom worlds easily in any genre or setting online for use at the tabletop!

Play for free as long as you want! Take your time to see just how flexible the Atomic RPG is with it's combination of digital tools, balanced rules, and ease of play.
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