DRILLS & GAMES
Operational skill comes from repetition. These drills and games build the reflexive speed needed for error-free field work.
9.1 Skill Matrix
Master each skill individually before combining them in the full pipeline. The matrix below tracks your progression.
| SKILL | DESCRIPTION | BENCHMARK |
|---|---|---|
| A | Mod-10 addition — reflexive, no conscious calculation | < 1 second per pair |
| B | Tens complement — reflexive, no table lookup | < 1 second per digit |
| C | Checkerboard encode — character to digit(s), immediate | < 2 seconds per character |
| D | Checkerboard decode — digit stream to character, sequential | < 3 seconds per character |
| E | Five-group transcription — error-free at operational speed | 10 consecutive groups, zero errors |
| F | Key stream discipline — position tracking, no reuse, no skip | 10 messages tracked without error |
| G | Full pipeline — integrate all skills under mild time pressure | 10-char message encrypted in < 5 min |
9.2 Drills
Each drill targets a specific skill. Work them in order. Do not advance until you meet the benchmark for the current drill.
Drill A-1: Mod-10 Flash
Partner (or yourself) calls out two digits. You respond with the mod-10 sum. No table. Do 50 pairs per session.
- Target: average under 1.5 seconds per pair by session 3
- Target: average under 1.0 second per pair by session 6
Drill A-2: Running Sum
Roll a d10 ten times, reading each result aloud. Keep a running mod-10 sum: after each roll, announce the new running total mod 10.
Roll: 4 → running: 4
Roll: 7 → running: 1 (4+7=11→1)
Roll: 3 → running: 4 (1+3=4)
…
This simulates chaining key stream addition.
Drill B-1: Complement Flash
One person calls a digit 0–9. Other responds with tens complement. 50 reps. Target: immediate response, no thinking.
Note the only non-trivial pairs: 1↔9, 2↔8, 3↔7, 4↔6, 5↔5, 0↔0. Internalize these.
Drill C-1: Encode Flash
Using the checkerboard (memorized or on card), one person calls a letter, other gives the digit code. Include both single-digit and double-digit characters. Vary distribution: include more E/T/A/O than Z/Q/X. 50 characters per session.
Drill C-2: Speed Encode
Write a short word (8–10 characters). Race against your partner to encode it completely. First to finish with no errors wins the round. Deliberately include Row 2 and Row 3 characters.
Drill D-1: Decode Stream
Partner reads a digit string (no spaces, 20–30 digits) at moderate pace. You decode in real time and write the characters. Evaluate accuracy.
- Variation: partner reads at 1 digit per second, then 2 per second after you reach accuracy benchmark.
Drill D-2: Cascade Detection
Partner encodes a 15-character phrase, deliberately introduces one error (changes one digit). Gives you the corrupted encoded string. You decode and identify where the corruption begins.
Drill E-1: Five-Group Transcription
Partner reads five-digit groups at dictation speed (one group every 3 seconds). You write. Verify group by group.
- Score: 1 point per error-free group
- Target: 10 consecutive groups with no errors
Drill F-1: Position Tracking
Use your practice pad page. Work through 3 back-to-back messages of varying lengths. After each, mark the page and log: message ID, page, start position, end position. Partner audits. One mis-mark is a failure.
Drill G-1: Relay Race
Two-person team. One encrypts a plaintext; hands ciphertext to partner who decrypts. Time the full cycle.
- Target: 20-character message in under 8 minutes combined
Drill G-2: Blind Relay
Same as G-1, but the encryptor does not tell the decryptor what the plaintext is. Remove the psychological crutch of knowing what to expect.
9.3 Games
Games add competitive pressure and ambient noise simulation. Play after reaching drill benchmarks.
Mod-10 Duel
Two players. Both roll 2d10 simultaneously. First to call the correct mod-10 sum of their own two dice wins the round. First to 10 wins.
Teaches: reflexive mod-10 addition.
Complement Hunt
One player calls a digit. Other must call its tens complement within 2 seconds. Failure (wrong answer or timeout) gives a point to caller. First to 5 penalty points loses.
Teaches: reflexive tens complement (needed for decryption).
Checkerboard Bingo
Pre-print 5×5 bingo-style grids of random characters. Caller encodes characters to digit sequences and reads the digits aloud. Players must decode the sequence, find the character on their grid, and mark it. First to complete a row wins.
Teaches: checkerboard decode under ambient noise (simulates real conditions).
Encryption Relay
Players take turns encrypting one character at a time (encode to digit, add key digit mod 10, write ciphertext digit). One mistake and your turn ends. Player who contributes the most correct ciphertext digits wins.
Teaches: single-character pipeline discipline.
Error Injection Challenge
One player fully encrypts a 10-character message. Secretly introduces one error in the ciphertext (changes one digit). Passes to opponent who decrypts and must identify the position and describe the nature of the error.
Teaches: error detection and cascading analysis.
Position Audit
One player encrypts 5 short messages on a practice pad, marking used positions. Partner independently audits the page by re-encrypting the same plaintexts and verifying that positions were consumed correctly. One missed position or overlap is a loss.
Teaches: key stream discipline and position accounting.
9.4 Practice Message Set
Use these plaintexts for all exercises. They are short enough to be tractable but long enough to require full pipeline operation.
Set A — Training
MEETING CANCELLEDPROCEED AS PLANNEDABORT AND RETURNPACKAGE SECUREDCONTACT TOMORROW
Set B — Intermediate
RENDEZVOUS AT BRIDGE ZERO TWO HUNDREDSUPPLY ROUTE COMPROMISED FIND ALTERNATEEXTRACTION WINDOW CLOSES AT DAWNTHREE AGENTS IN PLACE AWAITING SIGNALALL CLEAR PROCEED TO SECONDARY LOCATION
Set C — Advanced (Long Messages)
HOSTILE SURVEILLANCE DETECTED ON NORTHERN APPROACH REQUEST IMMEDIATE EXTRACTION AUTHORIZATIONDOCUMENTS TRANSFERRED SAFELY CONFIRM RECEIPT NEXT CONTACT IN SEVENTY TWO HOURS
9.5 Self-Assessment Schedule
| SESSION | FOCUS |
|---|---|
| 1–2 | Module 1 drills. Mod-10 only. No checkerboard yet. |
| 3–4 | Module 2 drills. Checkerboard encode/decode only. No OTP. |
| 5–6 | Module 4 worked examples. Encrypt Set A messages. |
| 7–8 | Module 5 worked examples. Decrypt Set A messages from ciphertext only. |
| 9–10 | Full pipeline on Set B messages. Introduce Games. |
| 11+ | Set C messages. Error injection drills. Speed benchmarks. |
Printable Reference
Download and print the dice games reference sheet for offline practice sessions.