reference check reference, check

WWJD

do anyone know how important a reference check is ? even for some basic entry level type of job..
i am going to have a few interviews recently, and they told me to bring them references, but one of them i didn't have contact for half a year and the other one may not like to receive so many calls/emails asking for references.

Is it possible that the company will still hire you even if they couldn't contact a reference, or if they have a bad reference about you ?