Subject Delta has a powerful arsenal in BioShock 2, from unstoppable melee attacks to devastating ranged weapons. Plasmids are wielded with weapons simultaneously and can be used at the same time. Unlike the first game, the player will have access to a quick-melee button, which causes Delta to swing whatever weapon he is holding in front of him. Although usually faster, this attack deals less damage than if the player is using an actual melee weapon. All ranged weapons have three different ammunition types. Weapons can also be upgraded at Power to the People stations as they could in the last game.
The Drill is a powerful offensive weapon, doing extensive physical damage. It can be used to deliever a direct uppercut, charge an opponent and knock them down, or drain its Health by direct boring. Unlike the Wrench from the original BioShock, the Drill consumes fuel and can be upgraded for decreased fuel consumption, greater damage and the ability to reflect bullets and projectiles.
The Rivet Gun is a single-shot, semiautomatic ranged weapon that fires high-speed Rivets. It is fast, accurate, powerful, and has low recoil. In addition to its base ammunition, its two alternate ammo types allow it to deal additional damage and deploy traps. Furthermore, the weapon can be upgraded to have a larger clip size, more damage, and a heating system that gives its Rivets a chance to ignite enemies.
The Machine Gun is a Gatling style weapon that fires .50 Caliber Rounds. It has a very high rate of fire, a high-capacity magazine and is capable of inflicting tremendous amount of damage before having to be reloaded. Along with standard rounds it can fire antipersonnel rounds or armor-piercing rounds, dealing more damage against unarmored and mechanical enemies respectively. The weapon can also be fitted with a damage upgrade, a recoil dampener and a bullet ricochet ability.
The Shotgun is a double-barrel, close-range weapon which fires Shells with wide blasts of pellets. It is a slow-firing yet devastating weapon up close, both on single and multiple targets. It can fire standard shells, along with metal slugs and incendiary ammunition. The Shotgun can also be upgraded to increase its damage output and clip size, and finally charge its shots with electricity at random.
The Spear Gun is a single-shot, long-ranged weapon that fires high-powered Spears. It is a slow-firing, but powerful and accurate weapon from any distance. Its base ammunition is capable of skewering enemies to the scenery, and its alternate ammo types allow the user to deploy electrical wires at will and fire pointed rockets which detonate after a set amount of time. Its upgrades can grant it more damage, a greater zoom and rifle-like projectile travel times, coupled with an increased firing rate.
The Launcher is the last gun Subject Delta gets in the game. It is capable of firing Grenades, dealing heavy splash damage to enemies, and can also fire Proximity Mines that stick to surfaces and Heat-Seeking Rockets that home in on targets. The Launcher can be upgraded for an increased clip size, an immunity to self-damage and a cluster bomb mechanism which splits the Launcher's ammunition into smaller versions of itself after detonation.
The Hack Tool is a tool for hackingSecurity Devices and Vending Machines at a distance through the use of Hack Darts. Its base ammunition requires manual input to hack machines, but one of its alternate ammo types can hack them automatically. Its third ammo type comes in the form of Mini-Turrets, which fire upon any enemy in their line of sight. The Hack Tool cannot be upgraded.
The Research Camera returns in the sequel, with a major change: instead of taking photographs, the Research Camera records videos. Research bonuses are now granted upon killing an enemy while recording, and killing the same enemy using the same technique yields a smaller bonus than the first time. However, there are still no upgrades for this tool.
The Ion Laser is a projected energy weapon that harnesses the power of light to create a precise and powerful beam, damaging enemies continuously. It can hold standard Laser Cells along with high-temperature ammunition, capable of setting enemies on fire, and another ammo type which can be charged up to deal damage in strong bursts. An upgraded version of this weapon can be found in Minerva's Den, and deals increased damage.