Hi all, I am just learning Deathwatch to run it for some friends. I am having a hard time understanding the Primarch's Curse rules and how the increase in level. Any help would be greatly appreciated.

Table 9-8 on p278 of the core rulebook shows what happens at different levels of insanity points. Once a Deathwatch character reaches 31 IP, they permanently gain level one of their Primarch's Curse. That remains even if their IP total drops below 31. Same story for the other levels. I hope that helps.

Thank you very much.