Spells from earlier campaigns in later ones?

lets say i own all 3 campaigns(proph, factions, nightfall) if i am playing in nightfall so i have the ability to train/capture spells from the earlier campaigns? I though that I only get the core and the campaign i am playing but some builds i have seen have multiple campaign skills.

Well, if you to Prophecies you get Proph skills as rewards from some quests, and also buy them. Elites you can cap.

Once you get a skill, you can use it in any campaign. However, usually you can only get the skill from the campaign it came from. If you have a Nightfall character and want Prophecies skills, you have to go to Prophecies areas and talk to the skill trainers there.

You could also unlock the skill first, then use a tome.

Heroes get to use any skills unlocked on your account.

ok, that pretty cool to know.

Ok you said if you have a nightfall character you can go to factions areas? How do you do that. Like how do i use my nightfall character in factions?

Well, first and most important is you had to have added your Factions access key to your existing account, not create a new account with it. In order to do that, log in to your account. When you're at the character selection screen, go to edit account, manage access keys, then add the key. If you didn't do this (and made a new account instead) you can't take your NF characters to Factions areas.

Assuming you did the above, there is a quest in Kamadan called "Plague in Cantha" that will take your NF characters to Factions. And if you wanted to take your Factions characters to NF, there's a quest in Kaineng called "Sunspears in Cantha"

If you did not link your Factions to your existing account, contact Arena Net support for help in resolving the problem. Remember that one of the accounts (your choice) will loose all characters and progress.