Unusable Enemy Equipment/Playing With

Basic Trope: A player can't pick up and use the equipment dropped by his enemies.
 * Straight: Drake regularly fights enemies with better firepower than him, but can't pick up any of the equipment they drop after defeating them.
 * Exaggerated: Drake fights enemies with weapons exactly like his, but can't take advantage of this to grab their extra ammo and equipment after finishing them off.
 * Justified: Enemies fight with parts of their bodies - Drake literally can't use them, as his biology is different from his that of his alien opponents.
 * Alternately, Drake's enemies use weapons with a security feature that prevents unauthorized people from using them. While this feature can be disabled, it takes much more time than Drake generally has available.
 * His enemies have a weapon that has instructions in a language Drake doesn't know.
 * Inverted: Enemies can disarm Drake and use his dropped weapons against him.
 * Drake's only source of supplies is whatever his opponents drop.
 * Enemies can disarm Drake, but still can't use his equipment.
 * Enemies fight with parts of their bodies, but Drake is still able to lop the part off, shove his hand in it, and pull a tendon or something to make it fire.
 * Subverted: Drake kills an Elite Mook and immediately scoops up his flamethrower.
 * Double Subverted: However, Drake doesn't have the training to handle the flamethrower effectively, and decides to leave it behind.
 * Parodied: Drake can't pick up enemy equipment because his enemies won't let go of their weapons even in death.
 * Deconstructed: Drake favors his vibro-hammer, so much so that he's not willing to use anything else. But he loses his hammer. It doesn't end well.
 * Reconstructed: Drake's vibro-hammer powers up as he uses it, so he doesn't want to weaken his primary weapon by using his enemies' guns.
 * Zig Zagged: Drake initially fights human opponents who drop usable weapons - but after the zombie outbreak, his inhuman opponents fight with their bare hands, and don't drop usable weapons. When he reaches the headquarters of the organization responsible, his hammer breaks, and all his supplies must be looted from the corpses of his enemies.
 * Averted: Drake makes frequent use of enemy equipment.
 * Enforced: The game-writers wanted better weaponry to be difficult to acquire, which is hard when he can just scoop up an Elite Mook's BFG after the first fight.
 * Lampshaded: "Why don't any of these guys have weapons I know how to use?"
 * Invoked: The Big Bad equipped all his troops with DNA activated weaponry; they only work with specific DNA prints from their registered users. If Drake tries to use them, they explode and deal damage to Drake.
 * Defied: Having acquired an enemy weapon with a security device installed, the hero goes with an specialist to disable said measures.
 * Discussed: "This isn't fair. The villains can plunder as much as they want, but if I try to take a fallen soldier's sword, I get yelled to death by this annoying fairy!"
 * Conversed: "Don't you hate it when in a game you can't use enemy weapons for no adequately explained reason?"
 * Played For Laughs: The villains have state-of-the art multi-function weapons while Drake only has a pointy stick. And much to his chagrin, whenever Drake tries to take one of said weapons, they just dissolve into mist.
 * Played For Drama: Drake is barely scraping by, outmanned and outgunned by the vast forces of the enemy. Their weaponry is passcode-locked and thus impossible for him to use, forcing him to scrounge and search desperately for anything he can use.

Too bad that Flame Trooper's flamethrower is too big for you to carry. Guess you'll have to go back to Unusable Enemy Equipment and see if there's a weapon you can use.