Originally posted by Sivaas_:

Originally posted by Suzaku:

RNG.

That simple? Okay. Thanks. Would've guessed the first raid would be set in stone so as to push for progression.

Not rng only but also your behaviour towards the creatures.
If you leave them alone as far as possible, you won't get raided that often.

The more creatures you kill, the further your progress is, the higher the chances of triggering a raid are.