The Gun resembles a futuristic handgun. As it becomes more energized, its power and versatility go up. It's present in nearly every Blaster Master adventure, held by Jason, Roddy, or Alex. The Gun's power level is derived from the suit of its wielder; if the wielder takes damage, the Gun's power level drops. At first, the Gun has a very short range and low power, but can fire quickly.
Regardless of the Gun's Power level, it is reduced to a basic peashooter outside of chambers. It's just as capable underwater as on dry land.
Collecting Gun Capsules will energize the weapon a total of 8 levels.
- Level 0: Short range
- Level 1-3: Long range.
- Level 4-5: Long range. Rapid fire has been replaced with additional curving bullets that arc around and behind Jason.
- Level 6-7: Multiple bullets are fired at once, creating a wave pattern of death in front of Jason. After a short range, the bullets lose their velocity. It's very hard to hit objects directly in front of Jason with this level, or in tight corridors since they collide with the walls.
- Level 8: Same as previous level, but the bullets travel through objects and do not lose velocity.
Jason's Gun is only capable of firing energy bolts and it never alters in power or projectile. It's given to him by Eve on his first on-foot excursion.
Jason's gun does not have its own energy source. Instead, it receives a permanent upgrade when Jason collects a power up shared with Sophia in the first stage, gaining rapid-fire properties.
Jason's Gun starts with 3 levels. Gun 1 will increase the Gun's power in Sidescrolling Mode, enabling it to destroy certain blocks, like the Crusher Beam. Gun 2 will increase the max level to 8.
- Level 0: Short range.
- Level 1-2: Double range of level 0.
- Level 3: Range extends to line-of-sight.
As opposed to previous users, Roddy's fully-powered gun isn't always a desired weapon. The short range of the flamethrower simply isn't suitable for many situations. It takes several hits for Roddy to lose any gun power under the maximum level.
- Level 1: Short ranged, weak shots.
- Level 2: The energy bullets now have a much longer range.
- Level 3: The Gun fires a spinning beam that gains width as it travels.
- Level 4: The Gun's rounds explode.
- Level 5: The explosions are more plentiful and powerful.
- Level 6: The Gun becomes a plasma flamethrower. Though short-range, it's damage output is very high.
The Gun is but one weapon in Alex's arsenal. It's moderately strong and has a high rate of fire. The Gun power up is known as a GP Generator which applies to Alex's other two weapons as well.
- Level 1: Standard single shot.
- Level 2: Higher rate of fire.
- Level 3: Lowered rate of fire, but double shots.
- Level 4: Increased rate of fire.
- Level 5: High rate of rate, the gun now has a wide range.
Like in Blaster Master, Gun Capsules are collected to increase the gun's maximum level. However, Jason can freely use any level of the weapon he has available, not just the highest one. Also, an Energy Guard can be collected that prevents your gun level from decreasing when damage is taken. It disappears after one hit, but regenerates over time.
- Level 0: Blaster - The default gun. Has a short range and low firepower.
- Level 1: Long Range - Fires long range shots.
- Level 2: Penetrator - Shots pass through walls and terrain.
- Level 3: Diffusion - Short range, damage increases as the target gets closer.
- Level 4: Auto Fire - Holding the shoot button sprays a continuous spray of bullets. The longer you hold the shoot button, the more the spread increases.
- Level 5: Reflect - Deploys a shield that deflects enemy bullets.
- Level 6: Striker - Fires a ball of lightning that penetrates walls and terrain. When it hits an enemy, a chain of lightning also strikes other enemies in range.
- Level 7: Flame - Holding the shoot button unleashes a short-ranged spray of fire. Enemies that are set on fire by it take extra damage. Can also be used to melt icy floors.
- Level 8: Wave - Fires a very powerful wide beam. The strongest multi-purpose weapon.