Friends are not necessarily actually friendly, but instead a cast of recurring characters the party will regularly meet.
These are used to create a sense of continuity in a travel heavy game, as well as provide the group of “secondary” characters often found in the whimsical travelogue stories Brighter Worlds wants to tell.
Start the Friend die at a d4, with all entries empty.
When the Travel Encounter result is Friend!, or when you need an NPC to appear in an unlikely place, roll the Friend die.
If there’s a Friend on that slot, that’s who is currently here.
If you roll an empty entry on the Friend die, choose (or roll) a new Friend for that slot. When all entries on the die are full, step up the size of the die with new empty slots.
This creates a slowly expanding cast of characters, ensuring familiar faces appear regularly, but always leaving room for newcomers.
The Cast & Crew chapter makes an excellent starting pool of Friends. Pick your favorites or roll randomly to select when you need to fill an empty slot.
Likewise NPCs from adventures you run can be added to the pool. In particular any character your players take a particular shine to or decide they hate. It’s a great way to keep fun characters, often developed at the spur of the moment, involved in the campaign.
Remember that these characters have their own stories, and own things going on. Their worlds do not revolve around what the players are doing. When a Friend appears, take a moment to figure out why they were be here, what they’re currently doing, and how either of those might intersect with the party’s current goals.
They should not usually begin hostile to the party, but may be working at cross purposes due to their own goals. Allow the relationship to develop across each instance the party encounters that particular Friend.