Attendance is not mandatory, but preferred.
The adventuring party will have a maximum of 5 player slots, and there will be 4 replacement NPC’s should players not be able to make sessions.
So as long as one player shows up the session will go on.
Player priority goes to players who attended the previous session.
And when accepting “tasks” players are asked to consider the Adventure length. If an adventurer is deemed to span 3 Sessions, its a good idea to prepare to attend 4 sessions to complete the adventure.
Mid quest is the only time players and NPC’s cannot be exchanged, as such abandoning your fellow players could have dramatic effects on their character’s well being.
What if I miss a session? what about my xp? my loot!
Your Charecter will advance with the party in xp, and upon obtaining a new level you will receive the difference in wealth. As such players who attend every session will generally be ahead in WBL but never XP