One way of helping the player narrative of a campaign is through Plot Points, a tool from D&D fifth edition.
Described in page 269 of the Dungeon Master's Guide for 5th Edition Dungeons and Dragons, they allow players to change the course of the campaign and introduce plot complications.
Each player gets 1 plot point which are refreshed if everyone uses them all. We used the basic option where plot points are spent to add a twist, NPC or complication to the scene or setting. The example is
A player can spend a plot point and state that his character has found a secret door, an NPC appears, or a monster turns out to be a long-lost ally polymorphed into a horrible beast
They give your players a bit more control of the world around their player.
How We Used Them
We introduced them to the generators campaign as I wanted the players to have more say in the narrative. They were an instant hit, especially among our newer players, although the veterans tended to hoard them.
They have been used to - Encounter a gnome merchant in the mountains (someone wanted a shortsword) - Find shelter in a old shrine to Mandark, the patron god of the party ranger. - Declare that the dumb tabaxi they met who proudly declared he was the smartest of his tribe, was actually the smartest of his tribe. - Let the party find various lilac-coloured pieces of clothing and equipment
Evolution at the Table
Although players were very happy with them, we made some changes as the campaign progressed.
Firstly, we refreshed at the start of each session, and ignored the limit of one plot point per session. Secondly, we got rid of inspiration, as players seemed far more engaged with the plot points. Thirdly, some players were holding on to them as a tactical advantage. To get round this we refreshed the plot points whenever only one player had them left.
They have become popular enough we have talked about using them in other games and campaigns. I look forward to using the third option "The Gods Must Be Crazy"
So this is an option that will give your players a bit more control over the game, and engage them more in the world around.
How have you used plot points in your game?