Combat is an extremely simple and automated procedured in Mechadroids. You simply specify another Mechadroid to attack through the game client and the battle routine will begin.
A battle is broken down into turns and a turn can represent any action or information that occurs within the battle (attack, defend, xp gained, credits stolen, etc). The main turn sequence in a battle is the attack and defend turns, whereby Mechadroids involved in the battle will take turns in attacking one another.
The frequency of attacks for each Mechadroid and whether they are successful or not are dependent on both Mechadroids' attributes involved (see the Attributes page). The damage dealt and received is also dependent on various factors, primarily which weapons and shields are being used by the battling Mechadroids (see the Techlab page).
After a battle, depending on whether you were victorious or not, you'll receive some experience points, which will advance your progression to your next attribute upgrade, and a portion of your victim's credits, which can be used to purchase weapons and shields in the Techlab.
Starting a battle also increases the heat of your Mechadroid by one point, regardless of the outcome. If your Mechadroid's heat increases beyond a certain threshold, it'll become overheated and will no longer be able to initiate any new battles. Heat gradually reduces over time, so if your Mechadroid is overheated, take a break and come back later for some more action!