Let’s face it, as a Dungeon Master it is easy to have gaps in your setting or environments a session is taking place. It is simply impossible to anticipate all the things the players will be interested in.
A way to deal with this is to simply let the player come up with these facts through a Narrative Skill Check. Players may use skills to create facts about the world and the environment. Narrative skill checks work like any other skill check, except they allow players to add setting fiction and specifics.
Any time a player wishes to make a statement about the setting, the player states what they want to make fact. The DM then determines the difficulty. The standard difficulty is DC 20, but the DM may increase the DC depending on the situation and the skill being applied. The player then rolls the die and the player succeeds, then what they stated is added to the setting fiction.
Albert is trying to find the local thieves guild. The DM does not know if there is a thieves guild, or where they might be located as he has not really defined many areas of the city. Albert declares, “The thieves guild is in an area called ‘The Gallows’, which is known for being a rough place.”
The DM considers the statement reasonable and says it will require a Streetwise check with a DC 20. Albert makes his check and succeeds. The thieves guild exists and there is now a crime ridden area of the city called the Gallows.
Players may also create facts about situations and encounters where which provide an advantage or change the scene. This allows players to creatively influence the game and provide the feel they are looking for.
Michelle in a situation where her character is captured by Orcs. Caught between in a rock and a hard place, she decides to make a narrative skill check. She states, “The orc culture demands that all challenges to authority must met by a personal duel. The winner of the duel is considered have authority over the tribe.”
The DM rules that this is a Nature skill check, and is a DC 25 check. If Michelle succeeds at the skill check, then this is a fact about orc culture.
This technique allows players to contribute to the setting and create little bits of fiction which can move the story ahead when the players become stuck, or something unanticipated occurs.