RenaTheRagDoll

Thank you, i still dont understant the cannon part, so if i take one character role no one else will? and how do i apply it to a rp?

The idea of canon basically comes from when they were compiling the Bible. There were a whole bunch of little books and scriptures and stuff, and the church went through them and decided which ones should be treated as "the one true plotline" (i.e. the canon) and which should be seen as merely interesting light reading material (i.e. the apocrypha).

Many works of fiction, such as Star Wars, inspire spin-off books, comics, etc. Fans (and occasionally also the original author...

...s) will classify these works as canonical or non-canonical. The canonical works generally don't contradict each other, and form the backbone of the fictional universe's history. Non-canonical works might contradict each other (because one author might not be co-ordinating his plot with another author) but they usually try to avoid contradicting the canon.