From “The Psychology of Immersion” by Jamie Madigan:
The game world also needs to behave as you’d expect it to. “Consistency is the single most important factor in creating a real sense of place,” says Josh Foreman, an experienced designer at ArenaNet who works on the Guild Wars games. “The style can be anything from photo-real to abstract to impressionism, as long as there is an internal logic to what the player perceives.” This means that in-game characters, objects, and other aspects of the world should behave like their real-world counterparts.
Interesting to read this in the context of dissociated mechanics in paper ‘n pencil roleplaying games.
It amazes me how someone can so thoroughly understand a problem and yet reach a conclusion so completely off-the-mark. If everything in an artificial world behaved exactly like it would in the real world, there would be no joy of discovery in the artificial world. The fundamental error that Jamie Madigan makes here is assuming that “internal logic” necessitates the *same* logic as is present in the real world. This is simply not the case.
The greatest strengths in video games (and paper’n’pencil RPGs) come from their ability to build up a new internal logic structure for the players to explore. The entire concept of the heroic adventurer is itself a departure from reality. Each game approaches the idea of the PC slightly differently, and immersion rests on the ability of the designers of that game (or that DM/GM/storyteller/etc) to make the world react to the PC in a consistent, believable fashion. This doesn’t mean borrowing from reality (although you can do that). It means that you establish some basic rules for the way things work and you stick to them. If you tell the players that a certain people wear a particular Hat, they need to actually wear that Hat. That’s really it.
I think the point is that the world behaves consistently for the character in a way that makes logical sense from the character’s point of view.
For example, the post earlier on spells as parasites tries to increase the immersion by explaining why wizards can only cast prepared spells once. If the explanation would make sense to the character in the world, that’s pulling the player into the immersion.
Contrasted to a “once daily” ability that you only do once a day because… well, for no reason besides you can only do it once.
I think the internal logic is addressing “because.” As humans we crave a consistency in our fiction because we cannot always get it in real life, so fiction generally must cohere more closely to storytelling “rules” than nonfiction.
If your fantasy premise is that warpstone is a material from the immaterial reality, and it causes reality cancer and can unmake things, triggering mutation and breaking the laws of reality to power magic more viscerally, then you can use warpstone in many ways and be consistent with the logic. Now warpstone can make deadly magic weapons, it can be studded in monsters to make them fearsome, it can be in a ring that allows a Chaos Champion to shrug off blows with a green crackle of light, and so on.
Sure, you could have magic weapons, big monsters, and protective rings without the warpstone. But with it there, the internal logic of what warpstone can do makes the world more immersive. If a character encounters warpstone, the character has a sense of what that means and why.
To summarize, internal logic is about having premises that support a conclusion. You can change the premises from our world, but the premises should still be consistent in the conclusion.