Defenders of Roma

Defences: +1 barricade (this_army)
Defences: +1 set of fire balls (this_army)
Defences: +1 set of spike traps (this_army)
Defences: +1 set of sudes caltrops (this_army)

-5% attritional losses when under siege (this_force)
Defences: +2 barricades (this_army)
Defences: +2 sets of fire balls (this_army)
Defences: +2 sets of spike traps (this_army)
Defences: +2 sets of sudes caltrops (this_army)
Increased missile attack range for all units (this_army)

-10% attritional losses when under siege (this_force)
Defences: +3 barricades (this_army)
Defences: +3 sets of fire balls (this_army)
Defences: +3 sets of spike traps (this_army)
Defences: +3 sets of sudes caltrops (this_army)
Increased missile attack range for all units (this_army)