Formal:
* Destiny: This is a classic word for an inevitable and predetermined course of events.
* Preordained: This implies a fate that is predetermined, often by a higher power.
* Inevitability: This emphasizes the certainty of the fate, making it impossible to avoid.
Informal:
* Kismet: This word suggests a fate that is predetermined, often by a mysterious or divine force.
* Writ: This implies a fate that is written in stone, leaving no room for change.
* Doom: This word emphasizes the negative and often tragic nature of the fate.
Other options:
* Foreordained: Similar to "preordained", but emphasizes that the fate was known beforehand.
* Unalterable: Emphasizes the fixed and unchangeable nature of the fate.
* Ironclad: Suggests a fate that is unbreakable and impossible to escape.
The best word will depend on the context and the specific tone you want to create.