How do fumble and dodge interact?

Do they stack multiplicatively? Or additively?


"Order of Defense
The enemies of humanity are relentless, but there are many methods available to keep yourself alive. It is important to know how the various levels of defense stack up. In order for an attack to land, it must make it through the following defenses:

-Fumble, Dodge and Projectile Deflection
-Chance to hit via Offensive Ability vs. Defensive Ability

Multiplicative as above. But powerful. Example CoS/searing light+ shadow dance and the likes+DA is still super strong

Chances for target to Fumble and Impaired aims from CoS\searing light\etc are not stuck, but one of them + chance to avoid melee/projectiles + DA work together.