The execution of Order 66 is one of the most tragic events in the entire Star Wars canon, though the subsequent Order 67 perfectly counteracts that darkness. In the final chapter of the Clone Wars era, Palpatine brought forth the culmination of his plots and schemes as Darth Sidious in Star Wars: Episode III – Revenge of the Sith. After corrupting the Chosen One Anakin Skywalker into his new apprentice Darth Vader, Order 66 was Palpatine's key weapon that turned the Republic into his very own Empire. However, things would have gone a lot differently had Order 67 gone into effect instead.
In the Star Wars canon, it's been confirmed that there was an entire list of contingency orders for the Republic's clone army, though Order 66 identified all Jedi as traitors to the Republic to be executed on sight. Likewise, the majority of the clones had secret behavioral modification implants ensuring that the order to eradicate the Jedi Order would be forcibly followed. In contrast, the less-than-canonical Order 67 is far more lighthearted.
