Continuity: Spock records a log entry as the "second officer". It appears they got "first officer" confused with "second in command."

Continuity: As the women are beaming aboard in the transporter room, McCoy's uniform switches from the standard blue tunic to his short-sleeved medical smock and back again between shots. (Time) Submitted by Jean G

Continuity: Kirk's says that it is Stardate 1329.8 in his opening log entry when the ship is in pursuit of Mudd's vessel. But after Mudd and the women have been brought aboard, Kirk's next log entry says that it is Stardate 1329.1.

Continuity: When the android Kirk boards the Enterprise and takes a "command pack," he walks out and down to the transporter, but he doesn't have the pack in his hand.

Continuity: When the android Kirk is created from the oddly short-legged blank, the turntable rotates to show Chapel the new Kirk - and the indentation on the other side suddenly disappears. (Time) Submitted by Jean G

Continuity: The landing party is out of contact with the Enterprise for two days because of the missing communicators. Wouldn't the Enterprise notice at some point and beam down some more, or make some other attempt to contact Kirk & Co.?

Continuity: The ropes tying Yeoman Rand to the chair keep changing positions (above her elbows or below her elbows) between shots. (Time) Submitted by Jean G

Continuity: The dust smudging both Spock's uniform and that of the older security guard instantly vanishes when they walk out of the building to go look for the onlies. (Time) Submitted by Jean G

Factual error: If Miri's planet is a "duplicate" (meaning identical) Earth, it should have clouds. It doesn't. This remains a mistake because "duplicate" means "exactly the same," and thus the clouds should be there. The special effects crew forgot to put them in. Noteworthy: the very first thing fixed in the digitally enhanced version of this episode was the duplicate Earth. It has clouds now. (Time) Submitted by Jean G

Continuity: For a penal colony, Tantalus V has really poor security. Van Gelder manages to escape with ease, by hiding a box - the only box - beamed up to the Enterprise.

Continuity: As Balok's 10 minutes are counting down, McCoy comes onto the bridge wearing a standard blue velour uniform. A few minutes later, when Spock says he can bring up Balok's image, McCoy is suddenly wearing his medical tunic with the different fabric and collar. Then when Bailey starts losing it, McCoy is back in the regular velour costume again. Submitted by Jean G

Continuity: Spock states that the Fesarius (Balok's ship) "must be a mile in diameter". Yet any one of the small spheres that make up the Fesarius dwarfs the Enterprise. If the Enterprise is about 300m long, the Fesarius would have to be around 6 km in diameter - considerably larger than a mile.

Continuity: After they've blasted the cube, Kirk and Spock are discussing repairs on the bridge. Spock's earpiece is in place one minute, but vanishes the next when the camera angle changes. (Time) Submitted by Jean G

Continuity: The landing party beams down in daylight, but the window inside Mendez's office shows that it's night outside. In the next exterior shot, it's day again. Next shot back in the office: night. (Time) Submitted by Jean G

Continuity: Kirk introduced Spock as "Lieutenant Commander" instead of "Commander".

Continuity: When Spock takes Captain Pike out of the briefing room, Pike appears, via the viewscreen, on Talos IV in the very next shot. There is no possible way Spock could have gotten Pike to the transporter room that fast. Submitted by Cubs Fan

Continuity: On the map of the area, in the Romulan Star Empire, the 2 planets where Romulus and Remus, but the map read Romulus and Rom II.

Visible crew/equipment: You can see the shadow of a boom mike on a tree just after the Caretaker appears.

Revealing: Stock footage turns the single plane strafing Rodriguez and Angela into two attacking planes for a moment. It becomes one plane again when it flies over Kirk and company. (Time) Submitted by Jean G

Factual error: When Spock beams down after calculating there was just enough energy left for him to do so, Sulu and Kirk watch him materialize, and Sulu says, "Someone beaming down from the bridge." From the bridge? Shouldn't he have said "from the ship"? No one ever beamed down directly from the bridge, but even if they could, how would Sulu know that's where they'd come from? (Time) Submitted by Jean G