From the Kickstarter page: This expands on what is found in the Starter Box rules including more ways to play faction special rules and more information about the universe of Leviathans.[1]

This book includes some material that appears to be adapted and updated from Leviathans Gazetteer.

Contents:

• Game Concepts
• Game Phases
• Firing Torpedoes Phase
• Movement Phase
• Resolving Torpedoes Phase
• Attack Phase
• Cleanup Phase
• Other Actions
• Other Parts of the Fleet
• Slots
• Methods of Play
• Terrain
• Scenarios
• The World of Leviathans
• Appendix A: Gameplay Examples
• Appendix B: Map Type Examples
• Appendix C: Tokens
• Appendix D: Gameplay Reference