Oil slick

Oil slicks are uncommon obstacles in the Mario Kart games. They primarily appear on standard road tracks, such as the Mario Circuit courses from Super Mario Kart, and cause drivers to spin out when they run over them. They are rather small and often placed at the edge of the road. Players can also jump (using a Feather) or hop over them. They appear in all but the first Mario Circuit in Super Mario Kart.

Oil slicks return in Mario Kart Wii on, Mario Kart 7 on , Mario Kart 8 and its Nintendo Switch port on and SNES Mario Circuit 2 in Mario Kart Tour. In Bangkok Rush, similar ink puddles appear in a section of the course where they are spit out by Inky Piranha Plants. Unlike normal oil slicks, these ink puddles will cover the screen with ink, similar to Bloopers.

Oil slicks also appear in Mario & Luigi: Paper Jam in the missions Wait Up, Yoshi! and Fly Guy Flyby, though they merely slow down Mario, Luigi, and Paper Mario.

Oil slicks appear in version 1.1.0 of Mario Kart Live: Home Circuit. Unlike in previous Mario Kart games, when ran over, it causes the oil to cover the screen and makes the kart hard to handle.