What do I do when I get attacked?

build troops, defend, take advantage of your doctrine. Arty, arty, arty and bombers. And always remember the terrain and to stack troops. Read the wiki for more info, ----> wiki.callofwar.com

Go for defensive troops that train fast: militia, infantry and anti tank. Those are the most efficient to make a defensive force fast. Also artillery and Anti Air can be a vivid choice for the reasons stated below.

Check their bonuses:

The Militia is a cheap defensive unit. Due to its slow speed and fast production time its main purpose is to defend own provinces and to surprise enemy attackers. - STEALTH: Militia is hidden in forests, hills, mountains and urban terrain when not fighting. They can only be revealed by Armoured Cars, Motorized Infantry and Interceptors with the same or higher level as well as by espionage.

25% extra attack strength in hills and mountains, 50% extra attack strength in forests.

Infantry is a defensive unit and the base unit of every army. It is cheap and easy to produce and important to conquer cities. Infantry is best used to defend against unarmored units.

Infantry has a 20% extra strength bonus in forests and mountains, 50% in cities.

Anti Tank guns are defensive units for countering attacks by armored vehicles. They are cheap and fast to produce but they should avoid fights against unarmored targets. - STEALTH: Anti Tank guns are hidden in forests and in urban terrain when not fighting. They can only be revealed by Armored Cars, Motorized Infantry and Interceptors with the same or higher level as well as by espionage.

Anti tank has 50% extra damage bonus in forests and 25% in cities.

You can also use artillery which is a ranged unit and can attack the enemy from a distance. You should stack them together so that they are effective.

Artillery is an offensive unit that is most effective against armored targets and buildings. It can bombard enemies from a safe distance without taking damage and should be placed behind other units while they engage in close combat.

They get 50% extra damage output in hills and mountains

Finally Anti Air is also a very good unit as it soaks up a lot of damage as it has a lot of HP

Anti Air gets 50% extra damage bonus in hills and 25% in cities.

Considering this is an emergency. I would use some gold if you have any? try to get some forts. maybe some quick defensive units. gold is best used strategically in situations like this

AMG Morgan wrote:

Considering this is an emergency. I would use some gold if you have any? try to get some forts. maybe some quick defensive units. gold is best used strategically in situations like this