When I started gaming, people tended to play Dungeons & Dragons with larger parties than now. When game session fell short of 8 or more players, dungeon masters often added their own character to fill the group. To me, the practice seemed dodgy. The spotlight belongs on the player characters. The players’ choices steer the adventure; their characters’ actions create the story.

Now, DMs never add their player characters to the party, but sometimes they get the same kicks by adding a pet NPC. These game-world Mary Sues let game masters indulge in wish fulfillment. They turn other NPCs into admirers and turn PCs into sidekicks. (Aaron at RPG Musings tells how to spot at pet NPC.)

Over my career as a DM, I’ve read countless how-to-DM guides. They all warn against letting non-player characters overshadow the PCs. I read this advice and probably shared a typical reaction: No duh. I never felt tempted to create a pet NPC, but I never even created an NPC who traveled with the players.

Lately, I have run some adventures that added NPCs to the party. To my surprise, the additions worked. They enhanced the game.

Out of the Abyss begins with the new PCs held captive. They meet other several other prisoners, and everyone joins in an escape. The PCs and NPCs find themselves deep in the Underdark, traveling together for as long as their paths overlap.

As the adventure progressed, NPCs left the group, leaving a pair traveling companions: Jim Jar, the gambling deep gnome, and Sprout, the young Myconid. I started to see them enrich the game. The ongoing characters became more vivid than the usual walk-on NPCs. The players enjoyed interacting with them. Players never care about the NPCs they meet in passing, but now they became emotionally attached to a silent mushroom boy.

Plus, the traveling NPCs served as guides. Most D&D players feel at home in a fantasy setting, but the Underdark should seem alien. The party’s Underdark natives helped me reveal the strange environment. They could give background information and show the way.

Walk-on NPCs could have met the party and dispensed information, but having a guide creates a certain economy. The players don’t need to keep meeting characters they never see again. Instead, the guides save time while they build bonds.

The adventure Cloud Giant’s Bargain also adds an NPC who guides the players. This adventure takes place in a typical (for D&D), flying castle, so its guide doesn’t help introduce the background. But this adventure aims to introduce D&D to new players, so instructor Tulahk guides novices through the adventure. He reminds players to do the sneaking, investigating, and diplomacy that will lead to success. Plus, Tulahk is crabby, talking skull, so when I ran the adventure, I had fun channeling J. Jonah Jameson while calling the PCs empty-headed boneheads and numskulls.

Despite the advantages of giving a party an NPC guide, only add them when they serve a role. And then keep the guide out of the spotlight.

To prevent a NPC from stealing the spotlight, follow two principles:

A guide can’t make decisions for the party. Either create a guide with little interest in the party’s goal, or make the guide too young, too foolish, or too weird to direct the party. Ed Greenwood prevented his NPC wizard Elminster from overshadowing players by making him eccentric. “I never wanted Elminster to be anything more than the ‘old storyteller’ figure,” Greenwood said. “He was the mind-wandering, irritatingly whimsical old man who could OCCASIONALLY be of help to PCs.”

The players must prove more capable than their guide. Tolkien understood the risks of letting a powerful figure upstage his main characters. He kept contriving to have Gandalf leave for important business elsewhere. If a guide reveals more power than than the PCs, the players will wonder why they showed up. On the other hand, if you mix in NPCs who the players can upstage, and who admire the PC’s exploits, the PCs shine even brighter.