The combat system in Dual Universe is still under development. However, combat is more about tactics than reflexes, because construct and player combat functions on a tab-targeting system, rather than an action (aim and shoot) mechanic.
Dual Universe is a single shard game where "Player versus Player" combat is extremely important and prevalent. Player combat can happen everywhere in the game universe except safe zone surrounding the planets of Alioth, Thades and Madis which makes up small portion of the overall playable area. However, no combat is possible in this safe zone.
Basic Combat Mechanics
In order to optimize technical resources, combat will operate on the standard tab-targeting approach found in most MMOs, with damage and hit chance being determined by stats, rather than aim. However, some weapons may have the lock and fire mechanism integrated into the operation of the weapon, with the locking tied to automatically initiate on whatever is in the center of the aiming reticle. Since Dual Universe is played in first person, this will give the impression of aiming. 
Construct vs Construct Combat
Construct combat requires that players man weapons elements on constructs. Players are able to lock and fire at targets by orienting the ship to face the target, or by rotating an individual turret.
The damage inflicted to the target will be automatically calculated, and voxels will receive damage in relation to their proximity to the point of impact.  A “damage sphere” will be calculated from the point of impact, and a variety of factors will affect how that damage is applied, such as the stats of the weapons, the type of damage, the presence of shields or armor, the type of material the construct is made of, and so on. Once voxels or elements receive a certain amount of damage, they will be removed from the construct, and will thus cease to function. Construct damage can also be applied to avatars, allowing for Construct vs Avatar combat.
See also Repairing
Larger ships are more powerful than smaller ships, and will be able to mount larger weapons. However, larger weapons will be balanced so as to be less effective at hitting smaller, fast-moving targets. Larger weapons will also require higher amounts of energy, which will require more and larger reactors to generate. Overall, larger ships will not necessarily be superior to smaller ships.
Dual Universe will feature different "environments" in space, such as asteroid belts, strong gravitational fields, or ionized clouds. However, these last two features may not be released until some time after launch.
Dual universe will feature a wide variety of weapons, each with their own strengths and weaknesses. Currently, there are four different types of weapons: Cannons, Missiles, Lasers and Railguns.
Cannons are Mid to Close range weapons which have a moderate firing angle, high rate of fire and a low capacity.
Missiles are Close range burst weapons that have a very high firing angle, high damage, fairly high capacity and a very high reload time.
Lasers are Medium range weapons that are the most forgiving out of the four weapon types. they have a medium capacity, medium firing angle and medium damage.
Railguns are Long range sniping weapons. They have high damage, a low firing angle, high magazine volume and the highest capacity out of all of the weapons.
- You can deal self damage if you shoot too close to an enemy.
- NQ-Nyzaltar, Official Dual Universe Forums, "Ask Us Anything" Event (Q&A 6)", https://board.dualthegame.com/index.php/topic/841-ask-us-anything-event/#entry8072. 07/06/2016.
- TheXPGamers YouTube Channel, "DUAL Universe: Developer Interview (Sci-Fi single-shard Sandbox game)", https://www.youtube.com/watch?v=m1WMwIDWFKI. 06/22/2016.