- Eras - The largest structural divisions of history; they define worldview, technology level, and political norms across generations.
- Wars - Sustained, large-scale conflicts that reshape borders, populations, and power structures.
- Catastrophes - Singular events with massive loss or disruption that permanently alter historical trajectories.
- Discoveries - Breakthroughs that redefine understanding, capability, or civilization itself.
- First Contacts - Initial encounters that expand historical context beyond known civilizations or species.
- Upheavals - Periods of instability or transformation that may not rise to full war but significantly shift systems.
- Conflicts - Localized or limited struggles with constrained scope or duration.
- Secret Events - Hidden or classified occurrences whose importance may only be recognized later, if at all.