Today, the promised few words about how the mechanism of telling stories can react to the actions of a player, and exactly when a player can see their influence on history. We can distinguish three basic reactions: immediate, total (cumulative) and delayed.
Immediate response to the player's actions are most common for quite trivial reasons. It is obvious that when a player kills an important character from the perspective of the story, this will never happen in her, or when the bridge blows into the air the enemy army after it does not pass.
Sometimes, however, you want the player's choices not to be so obvious or have no immediate consequences. You can then apply a delayed or summary effect.
The summary influence is based on the tracking of the player's actions for a long time, so that on the basis of his action the game mechanics could react appropriately. This is great for RPG games, where the game determines whether the player's behaviour was good or bad, allowing him to determine his character, and this in turn could affect the NPC's response to the player. Whoever played in the Baldur Gate knows that some characters will disconnect from our team if we proceed too well, or too bad.
The delay is still affected, which consists in postponing the visible reaction of the game to the player's actions. In several games, I met with a situation in which I could donate a life to a hero independent and let him go in peace, and this appeared to help me during some hard fight. This is precisely the effect of being delayed. Another example of the Let's be BioShock, where we can see the different endings of the game depending on whether or not always used sisters, only sometimes, or never.
I have met with the opinion that it is always necessary for the player to explain precisely that his consequences can have some consequences in the future. Not quite agree with that. In many cases this will be true, as it will allow the player to plan their actions in a more serious way. Sometimes, however, keeping this secret can have a positive impact on the story. However, you should be careful that the player does not feel cheated on the fact that the game did not inform him of the consequences of his actions. I felt sometimes uninformed at moments of character creation in RPG games. On the first approach to the game I never knew whether Kupiectwa skills would be important or whether the melee would be useful enough to combat firearms.
This is a matter that I will move in the future: How games reward or punish a player for his choices… And should they do that?