Weapon modifications in Going Commando are purchased with platinum bolts from Slim Cognito who then adds the bought mod to the specified weapon. Being featured in the series for the first time, there were only three available mods for purchase: the acid mod, shock mod, and lock-on mod.
Slim's mod vendors are located in Megapolis, Endako, the mining area, Tabora, and in Silver City, Boldan. On Endako, the vendor is found after retreading the "Visit Clank's apartment" with the Grind Boots and Swingshot, and using the Swingshot to latch onto a grind rail which will reach Slim. On Tabora, a mod shop is found close to the town. On Boldan, it is reached after completing "Ride the power lines".
Each weapon has one or two of the three possible mods available for it. The acid mod poisons enemies and causes afflicted enemies to take damage over time making the weapon more powerful against enemies with a lot of health, or when it can hit multiple enemies at once. The shock mod electrocutes any nearby enemies making most weapons more useful against groups of enemies. The lock-on mod allows the player to lock on to an enemy by holding and simultaneously, which allows for more precision aiming, while also showing the enemy's current health.
Behind the scenes
In early builds of the game, weapon mods cost regular bolts, rather than platinum bolts.