SGS works a bit differently from other game systems. This page will give you an idea of how it works.


SGS is firstly a toolkit for making games. It's a bit like a generic system, but instead of trying to come up with one set of stats, skills, creatures, and equipment for all genres, it instead allows you to tailor the game to the specific genre you want to play.

You might extend the fantasy.md game rules to play something very D&D-esque, you might extend the heck out of scifi.md to make it into your very own Star Wars game.

The point is that some parts of the rules will be the same across different genres, some parts will be similar, and some parts will be completely different, but they're all using the same underlying engine: SGS.


All of SGS revolves around "entities." An entity is anything that has game rules applied to it. Characters, monsters, weapons, armor, vehicles, NPCs, BBEGs, these are all entities.

All entities have the same set of possible stats. An individual entity will usually have several stats, but will very rarely have all the stats. What stats are available is defined by the game rule set you're using1.

Entities can own other entities. A warrior and his sword are both entities, for example, but they have different stats.


Entity stats are grouped into several categories:

  • Aspects & Flaws: These are descriptive phrases you can capitalize on using Tokens.
  • Primary Stats: These give you a bonus to several skills, and play a part in your defenses.
  • Skills: These are the active parts of a character. When you want to something hard, you pick a skill to roll in order to see whether you succeed.
  • Tactical Stats: These represent things like damage, range, speed, and other attributes that are important for combat.
  • Thresholds: These are your defenses. They protect you from actually taking harm.
  • Pools: These represent your health and other resources. When these run out, you're knocked out.
  • Equipment: These are the items, powers, and special abilities you have at your disposal. When you use an item, you add its skill value to your own for that roll, and use its tactical stats.
  • Limitations: These are traits that make a thing less valuable than its stats otherwise say. Generally they modify its availability or usability.

That's it. Everything can be represented with those stat groups.

Streamlined Core Rules

SGS tries to keep things as simple and uniform as possible, because time spent flipping through the book is time spent not playing the game.

Generally speaking, skills don't have specific sub-rules, they're instead used to accomplish whatever task seems within their purview. Sneaking past someone isn't fundamentally different from pumping them for information, for example.

Tokens & Aspects

Tokens are bits of narrative power that allow you to make use of aspects. Aspects are narrative descriptions about the scene, characters, or objects.

By spending Tokens, you get a bonus to your rolls, put a pentalty on an opponent, force them to act within an aspect, take an extra action, and much more.

You regain your tokens a number of ways, from accepting interference to good roleplaying.

How you use your tokens is one of the key ways that conflicts get exciting in SGS.

Value-based design

All entities have an experience value. This value is the sum of all the stats & equipment on the entity, multiplied by any limitations. This way, all entities in the game have an inherently balanced way of comparing them to each other. This allows you to quickly and easily compare the value of one magic sword against a full kit of mundane gear, or figure out how many heroes it'll take to bring down the dragon.

Core Game Mechanic

The basic game mechanic in SGS is as follows:

  1. Figure out what Skill is being rolled.
  2. Figure out if any equipment items are being used.
  3. Roll the die.
  4. Add your Skill bonus to the roll.
  5. Add the Skill's Primary stat to the roll.
  6. Add any equipment skill bonuses to the roll.
  7. Optionally spend Tokens to modify the roll.
  8. Compare your result with the target.

On pregen entities and those created with the apps, an entity's skills and the skills on its equipment are shown with two values. The higher of the two is the sum of that skill for that entity, ie it has already calculated steps 4, 5, and 6. Just roll your die and add the larger number.

System Components

SGS currently exists as a game framework, website, and set of apps. Since we're still in alpha, there's no actual book yet; this website is the book. The apps help you build characters and games quickly and efficiently, but you could do it all on paper if you wanted.

  1. scifi.md will have "small arms" in place of "archery" in fantasy.md, for example ↩︎