Reiterate This!

One mistake I see from a lot of GMs (and one that I've been guilty of before) is failing to reuse NPCs and places from previous adventures. This is a very easy mistake to make in the epic fantasy genre, which sees a lot of play. When you imagine an epic fantasy journey, it might sprawl over several continents, down into underground passages, and across multiple planes of reality. That said, it seems natural to leave behind the people you know from one place as you go to the next. After all, most of them are likely not adventurers and would be ill-suited to life on the road or in the abyss.

Fight the urge to leave people and places that the PCs know behind! Even in the limitations of a fantastic and sprawling journey there are still ways to keep the familiar around. Make sure to include an NPC now and then that's as capable or mobile as the PCs. A traveling merchant can reappear anywhere halfway reasonable (and if your group appreciates occasional silliness, the occasional unreasonable extra-planar location as well), and a lone wolf bounty hunter, while generally unwelcome in a cooperative party structure, has an excuse to show anywhere adventuring types might go as well.

Revisiting old locales is a snap as well. Hostile locations can be repopulated and modified by their new stronger inhabitants. Peaceful places can invite heroic adventurers back for a celebration on the anniversary of the region's liberation from the grip of a tyrannical warlord, which provides opportunities to revisit NPCs that aren't filled with wanderlust.

Revisiting past content has a number of benefits for both the GM and the players.

PCs can form relational identities - Whether players have come to the table with pages of history for their characters or just a sheet of numbers and gear, relationships with NPCs can provide opportunities to flesh out PC personalities. If a rescued orphan grows attached to a PC, for example, revisiting that NPC can be a tool for exploring the character's identity. What does the PC advise when the kid says he has a crush on the baker's daughter? How does the PC respond when he hears that the orphaned kid has been caught stealing twice since his last visit? Scenes like this forge a character's identity by revealing his opinions to the audience (the other players and GM).

Familiar context increases immersion - How many times has a player asked a GM at the beginning of a campaign, "Would my dude know this?" about one thing or another? Well, when you revisit old content, players know exactly what their "dude" would know about a place or person, because they built their familiarity with the content through the experience of play. It becomes easier for the PCs to stay in-character when they don't have to get context for their existence every few minutes.

GMs get more mileage out of great content - If you've taken the time to craft an intriguing locale or memorable NPC, shouldn't you get as much out of that effort as you can? It's easy to get wrapped up in showing the players the next new thing, but if you have any sort of life outside of the game, revisiting past content is a shortcut you shouldn't pass up. Any time you see the players have a strong emotional reaction to a piece of content, make a note that it would be worth revisiting.

Increased impact from the unfamiliar - If everything the PCs run into is always new, the impact of newness will slowly drift away. New becomes par for the course, and that's definitely not a good place for your game to be. Let your players take a break from the new now and then. It can get exhausting to craft new images in your imagination constantly for several hours straight. After some time spent with classic content, newness will recover the freshness and excitement that it should carry.

So next time you're strapped for game ideas as a GM, go back to your notes (or memories if you don't keep notes) and play your "Greatest Hits" album to your players. They'll enjoy the blast from the past and they'll remember how far their characters have come.