Greetings.
Are constitution retroactive, like toughness for example?
For example will be difference in my end HP if i start with 16 const and later boost it with 2 more or if i start it with 18 ?

 

Say my charater is with Constitution 16. At level 8, I increase the Constitution to 18, increasing the modifier from +3 to +4. When that happens will i receive increase in vitality for the previous level from 1 to 8 ?

 

Yes, retroactive like the Toughness feat. 

Thanks for the answer.
Im going to make Jedi Guardian and was thinking about starting stats.