I don't think I've seen force fields treated the same in any two games. As I was working on some super NPCs, I got curious about all the ways you can treat a force field power.
Does it absorb a set amount than burn out/shut down? Does that mean it absorbs 10 pts per attack for example, or does it absorb all of the first 50 points of damage and then dissipate? Does it require only energy to activate, or does it take extra energy for every point of damage it absorbs/blocks? Only certain types of damage? Would it be fun to treat it like a reverse damage roll and try to match the attack damage dice ("Okay, roll your 4D6 force field to absorb the gunfire")? Does it protect from mental attacks? Does it prevent incorporeal beings from passing through? Can you expand it to protect others? Does it block outgoing attacks? Is it airtight? Does it do damage to others when touched?
Let me simplify it down to one question: What is your favorite version of the force field?