I'm looking over the rules for Armor in the Gamma World 7e Core Book on page 72. It states that light armor, which grants a +3 bonus to AC still allows you to move around, and indicates no penalties. Heavy armor grants an enormous +7 to AC and only reduces movement by one.
Does the math behind the system in Gamma World expect that all players will wear armor of one sort or another?
Is there any mechanical reason not to wear armor as a player character?