I like Arnold’s idea. It forges a strong bond between the player characters with a common goal.
Since the setting of the Forbidden Lands is presented as a survival adventure game then you can use the following to start your game:
1) The players are at a staging post town just inside the Forbidden Lands for various reasons of their own. However, the fact that they are here means they’re not the typical members of their societies/kin. They are rogues and raiders!
2) They may know each other, but they all know that their odds of survival and success is very limited if they venture forth alone, especially since they all lack experience.
3) Since they’re all in the same place, at the same time, and with the same desire to travel farther into the Forbidden Lands then they will naturally form a mutual bond of survival.
4) The reasons why the player characters join up, as opposed to joining other groups, will mostly be due to having complementary resources and skills. For example, a spellbinder with a partial map joins a druid with some knowledge of the area, and they both seek a fighter with a high survival skill.
5) As they journey and fight alongside each other their bond grows stronger... changing from partners of necessity to battle brothers.
It’s simple and quick.