Rules Layers

The rules layers of SGS are like a pyramid

Think of the rules of SGS like layers of a pyramid. The deeper layers are more widely applicable, solid, and unchanging while the rules at the top are more transient, temporal, and subjective. The important thing here is this:

Higher rules depend on lower rules.

It's just like a real pyramid. The top stones are supported by all the stones below. In our case, the system rules support everything, and so on up the chain.

To discuss these, we're going to start at the foundation and work our way up.

System Rules

System rules are the meta-constraints on how a designer can implement SGS. The system rules include things like what the costs of stats should be, how entities sum their stats and equipment, that aspects and flaws exist and can be used, the fact that Primary Stats are not the same as Skills etc, that limitations exist and can reduce the value of entities, that how generated statistics can be created, and so on. System rules control how the game or campaign is set up. They do not deal with the implementation of the setup, or the specifics of the rules in a game/campaign.

Problems with the system rules are big problems, and are more difficult to fix, because they affect a lot of dependent content. Conversely, because the system rules are so abstract, they aren't likely to have many bugs in them.

Game Rules

Game rules are the implementation of the system rules for a specific game or campaign. Game rules include which Primary Stats exist, what Skills are available, how each stat works and what its domain is, in what ways players can use aspects, what generated statistics exist, how they're calculated, and so on. The game rules determine how the game is run. They don't deal with the fundamentals of stats, Xp calculation, and abstract gameplay structure, nor do they deal with the specific implementation of the game rules in a given entity.

Game rules are customizable per game/campaign, and that means that bugs in this category are pretty easy to fix, because the core system doesn't need to change. Some problems here are a little stickier, like balancing generated statistics, but are generally easy to patch because they're globally applied and non-specific. Changing the calculation for Health, for example, might cause you to recalculate all the health values for the entities in the game, but it's the same calculation for everyone, so it should be pretty easy to apply (especially with the software)

Entity Rules

Entity rules are the implementation of the game rules in a given entity. This includes which stats and skills a monster or character has, how good those stats are, what limitations they have, and what aspects or flaws that entity has. Entity rules only affect the entity itself and any entities that depend on it.

Entity rules are generally easy to fix because changing them has very little impact on the rest of the game. Changes here usually only result in changing the entity's Xp value and possibly the stat blocks of any entities that use the changed one as equipment. It's therefore easier to change the Block skill of an Orc Fighter than it is to change the damage of the Longsword, because many other entities are likely dependent on the Longsword and will need to be changed. The software largely negates this problem.

Rulings

Rulings are the implementation of entity rules & game rules in the process of gameplay. A ruling might be whether an aspect applies in a situation, whether a series of events requires a skill check, when the situation boils over into a combat scene, and so on. Rulings are generally subjective, but are usually given guidance by the system & game rules. Rulings happen because the system and game rules cannot pragmatically give rules for every situation and interaction between rules, players, and situations. The GM has final say on rulings, but may often defer to specific players or the consensus of the group. Rulings are dependent on all three higher rules levels.

Rulings are not generally the subject of bugs, because they tend to be single-instance situations with at least a moderate degree of uncertainty. If a game rule, for example, leads multiple GMs to repeatedly make the same problematic ruling, then the problem lies with the game rule rather than the ruling. Considering a single ruling a bug is difficult. If the ruling misapplied rules important to a character's agency or core themes, then the player should respectfully approach the GM about it after the game. If the ruling was bad but for purely expeditious reasons, then it's best practice to let it slide unless it becomes a habit that affects the whole game. If a ruling is in error (intentionally or otherwise) and nobody has a problem with it, then it's not an issue and wouldn't be considered a bug.