Season 1 was an enjoyable romp once it got the gang assembled, and Season 2 had an energetic Empire Strikes Back quality, but we're halfway through Season 3 and it's a turkey. New lackluster characters are being introduced into the gang, taking the focus off the old characters we actually like. The writers seem to have lost the thread of the story. At the end of Season 2 they set the audience up for a big showdown, but they deflated the tension in the very first episode. There are continuity issues every episode, such as, Why does Gisborne suddenly have a sister when he spent the first season moping about having no family? Did Gisborne's soldiers get eaten? Prince John was supposed to be angry about his tax money, but when Gisborne returns, it's to kill Robin Hood, not to squeeze money from the sheriff. With a few exceptions, most of the scripts feel as if they were hastily sketched out, without much care toward development of character or continuity. It's a shame.
The one exception to the lackluster season is Toby Stephens as Prince John. He's the perfect combination of insecurity, viciousness, and preening pomposity. He's very funny.