For my 300-level intro criminology course, I expect students to average
about 60-70% on the individual and over 90% on the team RATs.  The RATs are
10 questions and I specifically tell them that 7-8 are straightforward
(definitions, main ideas) and 2-3 are more challenging (application,
inference, projection, etc.).  The idea is that if everyone on the team is
prepared then they should be discussing the 2-3 challenging questions during
the team RATs, thereby learning the skills they need to figure out the
correct answers for those kinds of questions.

To help alleviate the stress, I post one set of sample RAT questions along
with a guide for preparing for RATs on Blackboard at the beginning of the
semester.  This illustrates the difference between an easy and a hard question.

I have also added an extra credit question for the individual part only.  If
they think a question was unfair or too picky but the team answered it
correctly (and therefore they cannot appeal it), then they have the comfort
of knowing that there was some compensation.  (BTW, this has not inflated
the individual RAT scores like you might suspect it would.)

I agree with the previous post re: student resistance. It gets much easier
to manage over time.