As a reaction, which you use when you are hit by a weapon attack that you can see, you can block the blow with a melee weapon you wield. Roll a d3 and add the result to your Defense against the triggering attack. You can do so after the roll but before any effects of the roll occur.
You can expend 2 additional stamina dice to roll 2d3.
You can expend 4 additional stamina dice to roll 3d3.