All Combat in Vendetta will take place in space, mostly between ships of various sizes, but also potentially involving stations and the like. PvP will play a big part in the game, as will Player vs NPC combat, or a mixture of the two. Conflict may take place on a rage of scales, from a lone pirate raiding a lightly defended transport, to massive interstellar battles involving hundreds of ships.

The essential combat itself is completely realtime and dependent on the user's skill and their character's equipment. There are no "virtual dice" being rolled to determine winner or loser, combat is all just as real-time and "twitch" based as any First Person Shooter. As such, there are some advantages to having a reliable, low-latency internet connection, such as Cable or DSL. However, the game was designed, from the beginning, to be playable on an average 56k modem connection, and by most accounts we're succeeding pretty well. Kills and damage are moderated and sanity-checked by the server, so bandwidth and "ping" advantages are minimized as much as possible.

The Flight Model of Vendetta amounts essentially to a user-configurable choice between "Physics" and "Arcade". The game itself functions in Physics mode: an action (such as engine thrust) will cause the spacecraft to move in a particular direction until it enounters another action (for instance, running into an asteroid, or an opposite engine thrust). There are some artificially imposed restrictions, like the "top speed", which are not strictly accurate compared to Real World. However, they do make for a more fun and entertaining game, and have been instituted for that reason. For the most part, Vendetta internally functions using the same basic physical principles that govern real-world objects in a zero-G environment.

From an Interface standpoint, a user playing in Physics mode may control the movement of their ship along any axis, thrusting in any direction. There are some short-cuts available, like the "brake", which tells the client (or your "shipboard computer") to apply the necessary forces to bring you to a complete stop. In practice, this means that a user of Physics mode may be thrusting their ship forward, then spin their ship around to engage an enemy behind them, while still traveling in the same direction ("backwards" once they turn around). This flight model has its tactical and control advantages, but isn't for everyone. For one thing, it requires paying more attention to your surroundings, since you're not necessarily facing the direction your ship is actually headed, which can lead to unfortunate altercations with large, inanimate objects (like stations and asteroids).

Arcade mode, on the other hand, uses a control system to simulate the properties of a classical "flight-sim" type of interface. Better suited to joystick players and fans of the flight models used by most other space games, this model automatically adjusts the ship's attitude thrusters to always fly forward in the direction the user points their ship. The user only needs to adjust their "throttle" to change how fast they're going. Again, this model functions as an auto-compensating interface layer that sits on top of "Physics" mode, it can't do anything that a user couldn't theoretically do on their own. But, it does make the ship much easier to direct and control under certain circumstances.

Both models are used very successfully by many players of the Vendetta Test. It's also possible to toggle between them, allowing a user to navigate normally using Arcade, but switch to Physics in the heat of combat.

The Interface Controls of Vendetta are configurable between: Keyboard, Keyboard/Mouse and Keyboard/Joystick. The game defaults to Keyboard/Mouse with Mouselook and Arcade mode enabled. Disabling mouselook will result in keyboard-only play. Mouselook functions by use of a secondary "target" reticle on the HUD, which represents the front of your ship. Whereever you face, the ship will turn to face your current direction. With mouselook disabled, your main HUD view is always "forward". Joystick users will need to configure their particular joystick, although default presets are provided for many common joysticks. There is no inherent advantage in using a joystick over the mouse/keyboard. Mouselook/keyboard is by far the most common, but some find it unsual for a "flight" type of game, and it's up to the user's personal preference. With mouselook enabled, especially in physics mode, the game tends to feel more like a fully-3D First Person Shooter than a traditional "flightsim" space game.