- A Guide to Constructed Languages - Conlangs and conscripts
- Japanese - With flashcards and quizzes to help memorisation
CRYPTOLOGY/STEGANOGRAPHY
- Pigpen Cypher (Freemason's Cipher)
- Null Cyphers/Acrostics
- The Substitution and Shift Cyphers
- Transposition Cyphers
- Ottendorf Cypher
- Create Hidden Messages in Noise
LANGUAGE GAMES
