King Arthur and Robin Hood are both cornerstones of British literary culture and traditions. They are both heroic, although they are heroes of radically different kinds.

Probably the most significant difference between the two is their status with legal authority. Arthur, as King, is the legal authority, and thus upholds traditional understandings of legitimate kingship. You can see this reflected in the classic image of Arthur drawing Excalibur from the stone. Robin Hood, by contrast, is always a rebel. He actively opposes the corrupt and abusive power structures of Medieval and Early Modern politics and society. In certain respects they embody similar ideals of justice and heroism, if from two very different perspectives. King Arthur represents the just king that fulfills his obligations both to kingdom and to God, a brave and pious warrior who embodies chivalry's idealized image of what nobility should be. Robin Hood, by contrast, reflects the breakdown of those power structures. He revolts against legal authority in order to obey higher moral expectations and defends the vulnerable against their oppressors.

These lead to additional divergences as well. For example, King Arthur tends to be far more honorable than Robin Hood. He generally upholds the ideals of fair play and honesty expected by the chivalric codes. It would be uncharacteristic for Arthur to go back on his word or to lie. Robin Hood is more complicated in this respect, given his extralegal status. As a bandit, he is far more willing to use deception and trickery to achieve his aims. He'll set up traps and ambushes or utilize disguises and subterfuge to avoid detection. However, while he will gleefully rob and manipulate the rich and powerful, he does not exploit or mistreat the truly vulnerable. Thus, despite his sometimes dishonest tactics—tactics that should perhaps be expected of a bandit and outlaw—he can still be understood as genuine in his convictions and essentially sincere.