The scale of the events reach across the globe, galaxy, the universe, reality itself, or across multiple realities.
Alternate names: Massive scale, Epic scale
Name variations: grand scope, massive scope, epic scope
The first video game about Grand scale was released in 1971.
For example, World War may not actually be grand scale because, for example, the historical ones affected only quarter of the world if even that much, and the second one was actually multiple wars happening roughly around the same time.
Available methods of travel can be taken into account for measuring what is grand scale. For example you'd need to involve quarter of a galaxy or more in Star Trek to make it matter for this tag.