Bonus Ratings:
 
You will get an extra rating or two or three just
for completing certain modes of play. In other 
words; if you complete Bounty Mode with statistics
to earn a C rating you will end up with a B rating.

 
Mode of Play                 Rating bonus

Complete Bounty Mode         1 extra rating level
Complete Scavenger Mode      2 extra rating levels
Complete Nightmare Mode      3 extra rating levels


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