The Gamesters of Triskelion
Kirk, Chekov, and Uhura become "thralls" who complete in gladiatorial games for the amusement of advanced beings - but Kirk's rebellious streak is more than they bargained for.
About the only novel aspect of this episode is that it's not Kirk, Spock, and McCoy who get kidnapped. Otherwise, we have the TOS equivalent of paint-by-numbers: Kirk forced to fight by super beings, but falls for the girl, rails against captivity, outwits the gambling brains. Okay, that last one sounded potentially interesting, but no, gambling brains are lame. At least in say, The Apple, there's a moral issue worth debating, but not so here. No one can really disagree with "Slavery is bad!" The shapes on which the thralls fight sometimes crop up in pop culture, but production values are pretty bad here. The drill thralls aren't attractive, so what Kirk sees in the "beautiful" Shawna is unknown. Of course, he might just like the planet's kinkier aspects: whips, collars, training harnesses. This stuff is not subtle - it leaps out at viewers. Chekov and Uhura don't get much development (though she remains a tough chick) , nor do those on the ship. For once Spock and McCoy's banter seems forced and grating, not amusing. The end recalls Arena, minus the suspense. The brains are probably the only ones interested.
Spock Saves the Day: Spock follows an ion trail to his captain, despite the objections of certain other senior officers.
Oops: He might have resolved tensions on the bridge sooner.
Developments: The Vulcan makes some attempt to counter his rigidity in the command chair with the cute "mutiny" moment. By suggesting Bones and Scotty are planning something more than continuing to complain, he actually eases the situation and reassures his doubtful officers.