VI. Character Leveling
If you intend to play longer campaigns, it’s beneficial to have a system for “leveling up” characters, similar to other popular role-playing games.
To keep things simple, OS-SIX uses a very straightforward “milestone” leveling system.
The GM decides when characters should level up based on their accomplishments in the game and how well the players have worked together as a team to accomplish objectives or just tell an interesting story.
On average, characters should be leveling up about every 3 - 5 sessions, but there is no hard and fast rule. Often the best time is when the characters have accomplished some kind of milestone in the game, such as defeating a particularly difficult challenge or mini-boss, for example.
How to Level Up
Whenever PCs gain a level, each player adds one point to one of their four core attributes (brawn, agility, mind, or will) up to a maximum of 5. Then each player rolls 1D6 and adds the amount rolled to their max HP, plus their Brawn.
Example: Eric's character has Agility 2, Brawn 1, Mind 2, and Will 1. He decides to add one point to Brawn. He then rolls 1D6+2, getting a four, and adds four to his max HP.
Note that some of the modules provide additional leveling information as part of the character playbooks.