There are six types of splicers. Thuggish, Leadhead, Spider, Houdini, Nitro, and Brute.

Splicers wander the corridors and tunnels of Rapture searching for ADAM (a genetic drug that gives superpowers like Fire, Ice, Electricity, Bugs, Machine Hacks, and many others.) Splicers tend to wear very little armor (if any), but they have increased physical strength and durability and tend to be extremely aggressive. They will sometimes work in groups, use Plasmids, and occasionally even play dead.