Vast, scripted stories aren't always the best idea for every video game. In fact, sometimes they just get in the way.
Final Fantasy Tactics A2, a tactical role-playing game by Square Enix, does not have an interesting plot, but with over 70 distinct jobs split among five separate civilizations, it provides one of the most diverse rosters in gaming history. While only a handful of characters have speaking roles, the game's largely open-ended nature allows for players bored with the story to create a better one on their own.
Need a fight scene? Go to a town and take a job. Want to meet a new character? Run around the map until you find someone you can recruit. Time to kill off a cast member? It can be done in three different ways: friendly fire, a suicide charge, or kicking them out of the group. The possibilities, while not endless, are nonetheless enormous.
Sounds great, right? Well, it isn't. Most of this content, from new regions to more advanced character classes, is locked behind the main storyline. This means before anyone can continue (or perhaps even start) their swift take-over of the world's criminal underworld (for example), they have to watch the “real” main character deal with hostile tomatoes.
The game would be much more fun if everything were open from the start, letting the player construct his or her own narrative as the game progresses.
This does not only apply to FFTA2 and its siblings in the genre. Imagine a detective story where instead of tackling one long case which grows increasingly complex as new victims and suspects arise, the main character is simply provided with a list of mysteries which he could choose to investigate at any time. The gamer could create their own assistants, whether constant companions (like Watson from Sherlock Holmes) or frequent consultants (like the recurring experts on NBC's legal drama Law & Order). A similar process could be applied to generating rival investigators, criminal masterminds, or even love interests.
The end result is freedom, the ability to control not only the actions of the characters, but the context in which those actions occur.
Early adopters of this style might feel lost without the carefully constructed worlds and casts which players have become so accustomed to, but once the foundations are established, it would be possible to rebuild some of the abandoned institutions. Pre-created supporting characters, the kind that form the basis of any modern single-player RPG's cast, can return to provide the colorful interactions which gamers expect. Quest chains can be introduced that provide extended narratives which supplement the assembled story in the same way as contemporary side quests.
The big difference would be that this time the whole product would be assembled around the consumer's choices, rather than requiring the player to work around the developer's idea of what should interest him.