The Water Margin
The character tree is a necessity to handle the deadliness of a DARK SUN campaign game. Since character mortality is a very real possibility, players are encouraged to make use of a character tree so that they have a range of characters already available for play in the event of a sudden fatality.
In general, a player should have at least one backup character in a character tree. This will provide an opportunity to introduce a replacement quickly in the event of character death, retirement, or removal from adventuring.
Character Tree Benefits
By providing a character tree, the player removes the burden of having to build a new character mid-game in the event of a fatality. This makes gameplay quicker and prevents any sudden halts. As a bonus, a character tree provides a minor benefit to the characters involved.
Shared Level Advancement
When one character gains a level, another character in the tree also immediately gains one level and moves to the minimum XP required for the new level. The character gains new possessions or money equal to the difference in expected character wealth for the two levels, as a result of background adventures, jobs, or good fortune.
You are encouraged to elaborate on the story of how your character gained this level and what happened in the background to provide the new-found wealth and skill.
At the end of any act in a story, when the party is situated in a safe, reasonably accessible location (given their resources and level), the player may choose to swap characters. The previous character leaves to do other tasks and the replacement character arrives to join the adventure.
In the event of character death, a character from the tree will be brought in as a replacement at the earliest opportunity.
Each character in a tree should have character ties to the other character(s) in the tree, as well as to the other members of the party.