Talk:Excalibur (Warframe)/@comment-50.156.49.18-20130620232412/@comment-190.246.3.132-20130621013407

Vitality and Redirection add to base HP and shield, respectively. Base is what it would be at Rank 0 (75, 100, 150, depending on the Warframe).

I'm guessing you have a 100 base shield Warframe (name Excalibur, for example). So:

100 * 2 (200%) = 200 -> 200 + 300 (Excalibur's Rank 30 shield) = 500.

Same for HP, that has the same numbers.