GURPS Crusades can be used a sourcebook for the following:
- Echo 1054-1291]] (the period covered)
- Low Fantasy Crusades Page 40
- High Fantasy Crusades Page 40
- GURPS Cliffhangers Page 40, 42
- GURPS Steampunk Page 40
- Crusader Victory Page 41
- Byzantium Revived Page 41
- Muslim Counterattack Page 41
- GURPS Arabian Nights Page 41
- Yrth Page 41
- Black Ops Crusades Page 41
- GURPS Cabal Page 41
- GURPS Faerie Page 41
- GURPS Horror Page 42
- GURPS Illuminati Page 42
- GURPS In Nomine Page 42
- Middle Ages Page 42
- GURPS Vikings Page 42
- Weird War II Page 42