NPC's or Non-Player Characters can be extremely helpful. In the classical RP sense of Dungeons and Dragons, an NPC often facilitates a party going on a quest, sells them the gear they need, or provides a nice boost out of the tavern if someone is drinking too much. They are temporary and somewhat disposable characters, usually without the benefit of a sheet or a bio. Other times they are the people who send player characters (PCs) out onto a new quest or mission and provide the reward for its completion.
A current list of NPCs within Molten Aether, see the Category:Non-Player Characters. Before playing an NPC reference the Non-Player Character Guidelines for how they can fit into an existing story.
NPC vs. PC
The differences between an NPC and a PC can get muddled. Especially, as often happens, when an NPC is used frequently for the same task. The main difference is in the focus of the plot / scene. An NPC should be a supporting cast member and not a main character within play. If a character is needed to be an integral part of play, players should consider making a full character.
NPC Approval
In our setting, NPC's may be used for this purpose without character approval, but one should be wary about back-dooring a character into play and should not introduce an NPC that doesn't fit the setting. We also emphasize the concept of player character exceptionality, where as player characters are defined to be exceptional. They are better looking, more skilled, and have more things they are allowed to do. An NPC should be some version of a regular person, not as exceptional as a player character on average. This doesn't always work but it should be considered -- if an NPC is absolutely amazing and awesome, why are they not the ones doing whatever important quest / mission the story requires?
Staff reserves the right to review NPCs as they are used and make corrections as necessary.