effortless
Done so easily it seems to take no effort.
Effortless means done without seeming to require any work or struggle. When a gymnast performs an effortless routine, her flips and twists look smooth and natural, even though she's trained thousands of hours to make them appear that way. When a skilled musician plays an effortless solo, the notes flow beautifully without any visible strain.
The word captures an interesting paradox: truly effortless performances usually require enormous effort behind the scenes. A student who glides through a spelling bee effortlessly has probably studied word lists for months. The best athletes, artists, and thinkers make difficult things look easy precisely because they've worked so hard to master them.
Something can also be genuinely effortless when it comes naturally or requires no real work at all. Breathing is effortless for healthy people. Making your best friend laugh might feel effortless because you know exactly what they find funny.
Be careful not to confuse effortless with easy. Easy means something doesn't require much skill or work. Effortless means it doesn't appear to require work, often because the person doing it has become so skilled that they make it look simple.