It's happened to me and when it does, apart from breaking immersion, it leaves me wondering why the modder did it.
As someone who spends a lot of time creating quest mods I tend to look at for articles on gaming sites which share insight into how to make quests that fit into the RPG world well - so that I can keep my quests 'friendly' or 'sympathetic'
I use the term here 'sympathetic' rather than 'lore-friendly' as I have found lore fans can get very unfriendly over mods which do not strictly adhere to their vision of Tamriel - a 'sympathetic' mod blends into the Morrowind environment in such a way it feels like it belongs and doesn't break a player's immersion even though it may not be true to lore - like a graphics replacer or a new weapon or a quest that bends the lore without breaking it
Anyway...
This article at Gamasutra is pretty good reading for modders who want to create 'sympathetic' mods it's called http://gamasutra.com/view/feature/185353/focusing_creativity_rpg_genres.php
It has a reasonable anolysis of Elder Scrolls games and the pluses and minuses this sub genre of RPG's has - here's a snippet
The Sandbox RPG
One of the most complex and costly subtypes, and thus pretty rare -- is the sandbox RPG, which includes games likeFallout 3 and the Elder Scrolls series. Here, the player is driven by the fact that she can do what she wants, kill what she wants, be what she wants -- and do it all when she wants.
That being said, there is a bit of paradox here; in order to obtain that freedom, and be able to create her own story, the player is willing to tolerate a lot of things that she would absolutely not tolerate in any other subgenre of RPG: immersion breaking bugs, average narrative, a simple combat system, etc.
For that reason, the focus of the production and features are clearly not on the critical path, as in a Narrative RPG, but on everything surrounding it: massive numbers of secondary quests, NPCs, places to visit, dungeons to explore, etc. And almost every single feature needs to support that freedom; some of the most important ingredients of the Sandbox RPG are:
One of the most complex and costly subtypes, and thus pretty rare -- is the sandbox RPG, which includes games likeFallout 3 and the Elder Scrolls series. Here, the player is driven by the fact that she can do what she wants, kill what she wants, be what she wants -- and do it all when she wants.
That being said, there is a bit of paradox here; in order to obtain that freedom, and be able to create her own story, the player is willing to tolerate a lot of things that she would absolutely not tolerate in any other subgenre of RPG: immersion breaking bugs, average narrative, a simple combat system, etc.
For that reason, the focus of the production and features are clearly not on the critical path, as in a Narrative RPG, but on everything surrounding it: massive numbers of secondary quests, NPCs, places to visit, dungeons to explore, etc. And almost every single feature needs to support that freedom; some of the most important ingredients of the Sandbox RPG are:
- Deep character creation, customization and evolution; remember, the player wants to be what she wants. If she decides she wants to be a thief-mage fighting with a two-handed axe, she should be able to do so (even if that might not be optimal). That's why good sandbox RPGs don't lock themselves in a rigid class system. At worst, the class system is simply a guideline for the player.
- Almost everything that the player would like to do should be doable, even if it is useless or potentially detrimental to her (like picking up brooms in Skyrim, or killing a quest giver). The player wants to do whatever she wants.
- Navigation should not feel restricted; yes, that means jumping, and no invisible walls. The player experience is freedom-based; not allowing her to jump would more or less consciously reduce that feeling massively. You will notice that almost only sandbox RPGs have a jump button -- that's the reason.
- A vast world to explore. The strength is in the details. Your world should feel alive; it should feel like it lived before and will live after the player's arrival.
- Non-linear progression. This should be obvious, but the player should feel free at all times to go where she wants, and never feel restricted by the story.
- As with the Narrative RPG, your itemization should feel "real", so avoid a random loot generator that could give "exotic" results, for example.
- Your narration needs to find a fine line between involving the player in your world and her story, and not being too big of a focus, so that she simply follows this and loses the "freedom" experience. Skyrim did a way better job than Oblivion in this area; the developers managed this by making you feel special -- you are The Dragonborn, ensuring that you feel important to the world, and thus the world to you, without making it the only thing that matters.
- Avoid a contrasted morality system (like Paragon/Renegade in Mass Effect). The only thing it will achieve is to make the player feel like she should follow one path over the other, and thus decrease the feeling of freedom.
Anyway am just posting the link as some modders might find it useful