Experience

The Great River Campaign uses the original Dungeons & Dragons rules for Experience instead of the rules in Worlds Without Number.

PCs and retainers gain XP primarily by returning with treasure from their adventures back to a safe town, or by "facing and overcoming dangerous opponents". Generally speaking, most sites have opportunities to make four times as many XP from treasures as from opponents. All the XP gained from an adventure are shared equally by all surviving PCs and retainers. (Though retainers require twice the XP to reach higher levels.)

XP from Treasure

XP from treasure are based on the value in silver pieces of all the things the party has picked up during the adventure and carried to a safe town. Treasure that is left behind or lost during the return journey does not provide any XP, but PCs can set out on further adventures to recover them. After the XP have been awarded to the characters in the party, the players are free to divide the treasure as they want.

XP from Opponents

XP from opponents are gained when the party was confronted by NPCs or creatures that either threatened them or blocked their progress, and the players successfully managed to get past that obstacle. To gain XP, the party must have been in danger of getting hurt and accomplished what they meant to do. Sneaking past guards does provide experience, but running from enemies until they give up does not. Ultimately this is at the discretion of the GM based on common sense.