The Role We Don't Play

RPG Codex has published an article entitled "The Role We Don't Play", in which they offer several reasons why today's RPGs fail to provide true role-playing.
In games like Baldur's Gate 2 or Deus Ex, the story was built so that it required certain characters to exist at all costs in order to keep presenting the narrative but developers still allowed players to try and go against the special rules created for these circumstances. This presented a clear issue developers gave players the ability to exert free will in the gameworld but did nothing to prevent these plot essential NPCs to come to harm, whether intended or accidental, with said will. Thus, attempting to kill certain characters for reasons such as quick quest advancement or role-playing specific personas - resulted in finding out they were invincible, or used instant kill weapons which they attacked the player's characters with if they tried to do something that the developers hadn't intended. Accidentally attacking one of these characters could even break someone's game. On the other hand, games like Fallout or Arcanum tried hard to provide something most other CRPGs don't do, which was to provide a gameworld that had several ways of story advancement. Important NPCs were either replaced by others or there were alternatives to further the narrative. One example in Arcanum comes to mind trying to find the owner of the mysterious ring eventually required players to investigate P. Schuyler and Sons in the city of Tarant. When the brothers were confronted, players who decided to fight against the brothers were not stumped. They could cast a necromantic spell to ask the soul of their dead father about the ring, could investigate the cabinet containing files about their customers, or even decide to remain silent about all the undead horrors they had seen in their basement in exchange for information.

The idea here is a more organic approach to narrative rather than the often stilted method of (our way or the highway) create context, don't force it.