The kinetic preference for 5-exo-trig over 6-endo-trig pathways in the intramolecular radical [2 + 2] cycloaddition of 1,5-dienes governs selectivity, a phenomenon dubbed the rule of five. Now it has been shown that subtle electronic tuning can enable programmable regiodivergence under visible-light energy-transfer catalysis, giving access to either bridged bicyclo[2.1.1] or fused bicyclo[2.2.0] scaffolds.