Jamal Walker (Martin Lawrence) is a workshy medieval theme park slob who finds a mystical medallion that sends him back to 14th-century England. Mistaken for a messenger, he has assorted wacky adventures and helps to oust an evil queen.
Yes, we're in Connecticut Yankee In King Arthur's Court territory, and Mark Twain is spinning so rapidly in his grave that he's tunnelling to Australia. But this Lawrence vehicle just about remainson the comedy road, despite some truly lame gags.
With anachronism (claiming to be "Sir Skywalker", Jamal brings funk to the palace), fish-out-of-water confusion (his accent makes people assume he's French) and a standard snarling villain (Vincent Regan), Black Knight isn't so much written as assembled by randomly selecting numbered balls and matching them to a list of story points - a national plottery, if you will.
If you enjoy Lawrence's usual schtick, you'll get some laughs from this. Everyone else should stick to something fun. Trial by fire, maybe?