Warp loop
So now city B dispatches troops to fort A. Rather than returning to city B the troops return to city A (the original occupying city)
and vice versa
Below city A occupied a distant fort (A) next to city B.
And vice versa.
City A <------------------- fort A
\/ /\
.Fort B -------------------> city B
Now instead of marching between cities, city B simply sends troops to the nearby fort A. Then call back to "warp" your troops to city A
And vice versa.
Hours of travel time now takes a few minuites!
City A <------------------- fort A
\/ /\
.Fort B ------------------> city B
Example of a warp loop
Nathan05
S106