Some temporary advances that a nation can obtain will give that nation the ability to do splash damage. The higher a nation’s Splash Damage stat, the more splash damage that nation can do. When a nation attacks with splash damage, it does the normal amount of damage to the square that it directly attacks, but it also does a percentage of that amount of damage to all enemy squares immediately surrounding that square.
Because attacks with splash damage cost more manpower than normal attacks, they are typically used tactically in specific circumstances rather than with every attack. Because of this, attacks by nations with the Splash Damage stat will not automatically do splash damage. Instead, to trigger an attack with splash damage, right click (or press and hold on mobile) on the enemy square you want to attack and select Splash Attack from the menu.
If you’re using a device with a keyboard, you can click (or tap) to attack an enemy square while holding down the Shift key, to make it a splash attack.
Next: Critical Hits