Day of Battle – the Norman Conquests source book is a supplement for Day of Battle – the Middle Ages. It includes: New rules Official new and modified Domains Rules clarifications Multiple campaigns To use this sourcebook a player will need a copy of Day of Battle – the Middle Ages. With modifications most of the information provided here can be me used for most other game systems. Such modifications are left up to the reader. The information within this sourcebook as well as the main rules is not set in stone. Players may agree to change any rules that they don’t think quite fit in with their playing style or view of history. —description from the publisher