There are two sides, Allies and Axis, which each control regions. A region is a fixed geographical area, controlled by at most one side. A region has infrastructure consisting of all buildings except civilian houses. A region can also be home to a number of airfields, which have their own infrastructure (typically hangars, fuel tanks…).
Regions are connected by roads and railways, which can cross rivers with bridges. Roads and railways have a transport capacity. Bridges can be destroyed, resulting in a loss of capacity in the transportation network. Destruction of infrastructure in a region affects transport capacity into and out of that region. If all infrastructure is destroyed, the transport capacity is halved.
At any given date, a region can be occupied by ground forces, characterized by a number. Both sides can have forces in a region simultaneously. When a region has forces from one side only, that region falls under the control of that side, and will remain so until the other side enters the region with their forces, while the until-then controlling side has no forces there. Regions can also be captured as the result of a battle, when the forces belonging to the side controlling the region are defeated or surrender.
Ground forces are simply characterized by numbers, the exact breakdown by vehicle type is not tracked.
Airfields host planes, which are accounted for: A plane can be added at an airfield by landing there, and removed by taking off. Planes can be (partially) damaged. Planes are counted as "volumes", meaning that two planes damaged to 50% count as a single healthy plane.
Both planes and ground forces are replenished at regular intervals. They materialize in so called entry regions, of which each side has at least one.
The effectiveness of ground forces and the speed of repairs to infrastructure is affected by connectivity from the region (where the forces or assets are located) to the entry region(s). Forces in an isolated region have reduced efficiency during battles.
Planes and ground forces can be destroyed during gameplay, but also between missions as part as simulation. The simulation covers battles between ground forces, transfers of ground forces, air missions. Air missions consist of attacks and patrols. Air encounters are simulated, and the results are affected by respective number of participants and their experience.
The experience of an air force is affected by its home airfield and the availability of experienced pilots. Pilots are controlled by players, and their achievements, health and location is tracked.
Whenever a player takes off from a new airfield, they take control of a fresh pilot. When they land back at an airfield, or at least near an airfield, that airfield becomes the new location of that pilot.
Pilots can be injured, in which case they become unavailable for a period of time that depends on the injury. New pilots are introduced as needed.
Pilots gain experience by flying missions in which "interesting things happen", typically they inflict damage to the enemy, or receive damage from the enemy. Alternatively, long flights count also as granting experience.
The number of pilots and their experience at each airfield affect positively the simulation of all missions that originate from that airfield.
Experience is divided in domains, where each domain is identified by the rough size of the target (large or small), its mobility, its environment (air, ground, sea/water) and the type of weapon used (currently limited to bombs and "the rest").
There is a hierarchy of domains according to difficulty, and the experience in a more difficult domain is applicable in an easier domain. Note however that experience against airborne target and ground targets are distinct, and experience in one of these two domains cannot be applied to the other domain.
What to do
This sections suggests missions.
Look at the map, identify bridges in enemy territory which the enemy must traverse to reach the front. Roads in neutral regions or outside the play area (but within the convex hull of the play area) are accessible to vehicles of all sides. Destroying such bridges will prevent reinforcements, and diminish a region’s fighting ability. Depending on the availability of ground forces in the region, some of the bridges may have active anti-air defenses.
Patrol for enemy camps
Fly around on the map, below 3000m. If you come close to an enemy camp, it will appear on the map in the game. If you are in a fighter, you can attack the camp’s anti-air defenses. Get some altitude out of range of the anti-air defenses, then dive in at high speed. Bob and weave a bit to throw the aim of the enemy’s cannons off. After shooting and destroying one or more cannons, extend at max speed, low altitude, bobing and weaving, for at least 3km. If you get hit disengage the target and try to make it into friendly territory.
Destroy enemy camps
After AA defenses at a camp have been destroyed, you are free to attack the vehicles there using cannon, bombs and rockets.
Patrol for enemy planes
Enemy attackers, when in the air, are marked by an icon on the map. The icon is located near the target area, not the planes themselves. Fly to the area, then either circle there waiting for the planes to arrive (which can take up to 45 minutes!), or fly towards the enemy’s airfield where you guess the attackers are starting off. When you encounter the planes, shoot them down.
Attack enemy airfields
Similar tactics as for attacking anti-air defenses of camps, using fast fighters. Note that AA defenses respawn after a few minutes at rear airfields, so don’t hang around for too long after destroying them. You may also want to leave the anti-air defenses alone, and do a single pass with bombers. Aim for hangars and static planes on the ground. Fuel tanks are also targets. Destroying hangars and fuel tanks prevents AI missions to start from that airfield. Destroying planes prevents AI missions to use them, and players to spawn in them. Effects apply in the next mission, not the ongoing one.
Attack enemy infrastructure
This includes factories, train stations… They may be protected by relatively weak AA if troop presence in the region supports it. Best attacked using multiple medium-sized bombs. Destroying this infrastructure limits reinforcements and supplies (for repairs and fighting efficiency) travelling through the region.
Attack enemy convoys
Trucks and trains are marked on the map while travelling. The icon marks the road or rails where the convoy travels, not their current position. Destroying a convoy removes the corresponding amount of ground forces.