The authority to detain entrants is given to the inspector under certain conditions, usually when an entrant severely violates the immigration protocol, or under other circumstances. Detaining is possible starting on day 5 in story mode. The detainment animation usually takes around 6 seconds, except when guards have to knock out entrants.
When a discrepancy or other reason that warrants detaining an entrant is detected, a blinking detain button appears. Pushing it will trigger a short animated sequence (see below). While the sequence plays out, the in-game clock keeps ticking, so detaining takes time from processing entrants. If playing endless mode and in most cases in story mode, it is possible to just refuse entry even if the entrant could be detained.
In story mode, detaining entrants becomes profitable due to a deal Calensk makes with the inspector on day 9. The timed and endurance variants of endless mode also compensate the player for detaining entrants: In the timed mode, a detained entrant adds 5 seconds to the timer (and one point), and in the endurance mode, a detained entrant is worth two points (while a processed entrant otherwise is worth only one point).
Situations for detention
The inspector is able to detain a person after identifying a discrepancy involving at least one of the following conditions:
- Alias database does not resolve discrepancies in names.
- Fingerprints do not match between the fingerprint slip, the person's printed M.O.A. identity record, the Grant of Asylum, or the identity supplement.
- Body scan reveals contraband or weapons, or incorrect sex.
- Entrant's identity numbers do not match.
- Dates of birth in different documents do not match.
- Seals on documents are missing or not valid.
- Issuing cities on documents do not match the country or are misspelled.
- Districts on an identity card do not exist or are misspelled.
- Diplomatic Authorization document does not list Arstotzka.
- Entrant is a wanted criminal.
Invalid detention reasons
The inspector cannot detain people with the following discrepancies in their documents:
- The person is missing required documents.
- Documents are expired.
- Certificate of Vaccination does not have an up-to-date polio vaccination.
- The entrant's Work Pass will expire before the expiration of time limit imposed by the duration field of the Entry or Access Permit.
There is a glitch for the iOS version, which forcefully detains the entrant. It involves the player to tap at the exact border between the counter, and the space below the counter, above where the detain button would be.
Animation when detained
When the detain button is pushed, an alarm will sound, the shutter closes, and two guards walk to the booth. Between days 5 and 15, the two guards stationed in front of the wall will handle detentions. Since day 16, two guards appear from the top of the screen. The left guard will demand the entrant to exit and they escort the entrant off-screen. Until day 16, the guards return to their original position afterwards.
Three entrants, the fourth entrant on day 10, possibly Danic Lorun on day 21, and the first entrant on day 24, refuse to leave the booth when detained. The left guard then demands them to exit the booth and the right guard knocks them in the head with a butt of a rifle and apprehends them.
The player may call in the next entrant when the detained entrant has left the booth.