Gambit is a turning point in Blakes 7 for several reasons. Visually it is by far the most outright camp and fabulous of any episode up until this point, and sets the tone for the following season in that respect.
The other main way it is a turning point is the way that Blake is no longer clearly the main character in the series named after him, and for this story is confined to only one of several interconnected plotlines - not even the one with the most screen time.
The main plot thread of Gambit sees Avon, Vila and Orac performing a Mission: Impossible-style caper in the casino of Freedom City, which is run by the villainous Krantor.
Krantor is playing host to Servalan, who is accompanied - for this episode only - by the most randomly Scottish henchmanny imaginable. His job is to be somebody for Servalan to give the exposition to - but cleverly she is not just giving it to us, the audience, but in the story she is giving exposition to Krantor who is secretly listening to and plotting against her.
Servalan also breaks her usual habit of wearing white, competing with Krantor for the most fabulous costume in the episode.
This is Krantor and he has a cat! As Krantor is a baddy then it is probably a bad cat, unless it is being held hostage by Krantor in which case I hope Avon and Vila rescued the cat as part of their plan. Sadly the cat has no lines so I don't know.
Blake, Jenna and Cally, in their Space Western subplot, are looking for Docholli (who was the manny Space Major Provine told them about in Countdown, and whom they hope will tell them where to find Star One) but they meet Bill Filer from Doctor Who's Claws of Axos instead.
Travis has his own subplot too, as he makes the transition from Federation officer and chief henchmanny of Servalan of the earlier stories into the ultimate baddy he will be in Star One. His line "Oh yes, I'm a hero too," says much about who he wants to be as opposed to who he has become. He seems pathetic when captured by Bill Filer and then Servalan, and when he needs Docholli to fix his robot arm - a tragic character that you could almost feel sorry for - but switches instantly back to dangerous as soon as Blake appears.
Blake doesn't get the location of Star One from Docholli, but he does get another clue that leads to The Keeper, so a partial success there.
Krantor (no sign of his cat in these scenes) catches on to Avon's plan to win all his money and he drugs Vila so that Vila agrees to play Speed Chess against Ze Klute, and Ze Klute always kills anybody he beats.
Avon's reaction to this turn of events is priceless, one of the best moments in the episode, because at this point he doesn't know Vila has been drugged so he thinks Vila must have volunteered to play.
Vila comes to his senses when he is already sat next to Ze Klute and looks scared, but you can see from Avon's face that he has a plan - he thinks Orac can win at Speed Chess just as he won at the gambling.
Ze Klute concedes a draw to Orac, so Avon and Vila win 10 million space pounds (or whatever the currency is meant to be), breaking the casino and defeating Krantor.
Back on the Liberator, Blake is suspicious that Avon and Vila have been up to something while he was away doing the proper plot.
Vila and Avon try to look innocent and say they just had sleeps and "played a little chess." Blake would be angry if he knew they had been having a much better subplot than him!