Directive 10: Binary Hour (Hints & Answer)
Hint first (no full spoiler): Check your clock, take the hour in 24-hour local time, and convert that number to base 2.
Directive 10 requires your password to contain the current hour, in your local 24-hour time, written in binary. The Vault Security Committee considers this a reasonable request. The Committee does not consider your time zone, your bedtime, or the fact that the clock keeps moving.
The full solution
Take your local hour as a number from 0 to 23, convert it to binary, and type the digits into your password. Hour 13 becomes 1101. Hour 0 is just 0. Hour 15 is 1111.
No conversion needed, just look it up:
| Hour | Binary | Hour | Binary |
|---|---|---|---|
| 0 | 0 | 12 | 1100 |
| 1 | 1 | 13 | 1101 |
| 2 | 10 | 14 | 1110 |
| 3 | 11 | 15 | 1111 |
| 4 | 100 | 16 | 10000 |
| 5 | 101 | 17 | 10001 |
| 6 | 110 | 18 | 10010 |
| 7 | 111 | 19 | 10011 |
| 8 | 1000 | 20 | 10100 |
| 9 | 1001 | 21 | 10101 |
| 10 | 1010 | 22 | 10110 |
| 11 | 1011 | 23 | 10111 |
Example fragments that pass at 3 PM (hour 15): mali1111, 1111ski, Fern1111!.
One warning the Committee stamps in red: the rule tracks the clock live. Play across an hour boundary and the directive re-breaks, floating back to the top marked DENIED. If it is 3:58 PM, either type fast or plan to swap 1111 for 10000 in two minutes.
What breaks later
The binary string is a fistful of 0s and 1s, and those digits ripple through the rest of the run:
- Directive 8 counts every digit. Hour 15 (1111) adds 4 to your digit sum. Hour 16 (10000) adds only 1. Late-night players at hour 23 (10111) add 4. Re-balance your other numbers to keep the sum on a perfect square.
- Directive 19 asks you to exile characters, but 0 and 1 can never be exiled, precisely because this rule needs them. The Committee thought of that. Do not build an exile plan around dumping your binary digits.
- The 0s and 1s also count toward whatever digit palindrome you build for Directive 11. Hours like 9 (1001) and 15 (1111) are already palindromes on their own, which is the closest the Committee comes to a gift.
If your session runs long, note the next hour’s binary form from the table above before the clock turns. Fern grows on a schedule. So does the clock.
Stuck on a different directive? Browse all 30 rule guides or return to the vault. Fern believes in you.
Frequently asked questions
- What is the answer to rule 10 in The Password Games?
- Convert your current local hour, 0 through 23, to binary and include it. For example 1 PM is hour 13, which is 1101 in binary. The answer changes every hour, so it depends on when you are playing.
- Why did rule 10 suddenly break while I was playing?
- The rule checks the current hour in real time. If the clock crosses an hour boundary mid-run, the old binary string no longer matches and the rule re-breaks. Update the binary digits to the new hour.