The rule regarding using power-lighted equipment on bows for big game hunting is: "It is unlawful to pursue or kill big game animals with any electronic or tritium-powered device attached to an arrow, bolt or bow. Except disabled archery permit holders may use a nonmagnifying sight with battery powered or titium lighted reticles."
Tritium is considered self-powered because of the emission of electrons created by radioactive decay causing phosphors to glow. Light produced by tritium can be indistinguishable from light produced by a battery.
Because the rule precludes the use of tritium sights, it would be unlawful to hunt big game with them in Idaho.