Showing up to a gi class for the first time is simple: someone tells you to buy a gi, and that's the uniform, no ambiguity. No-gi is less obvious, since there's no single required item, and a lot of first-timers either overbuy specialty gear they didn't need yet or show up in something that actively works against them on the mat.
The Basics That Matter
A rash guard, a snug, moisture-wicking long or short sleeve shirt, is the closest thing no-gi has to a required item. It prevents mat burn, manages sweat, and doesn't give an opponent loose fabric to grab the way a regular t-shirt does. Paired with that, grappling shorts or spats without pockets, zippers, or belt loops are essential, since any of those can catch a finger or toe during a scramble and cause a real injury.
What to Avoid
Regular athletic shorts with pockets are the most common first-class mistake. A finger caught in a pocket during a scramble is a genuine, if usually minor, injury risk, and most gyms will ask a new student wearing them to change or borrow something before rolling live. Cotton t-shirts are a lesser but real problem too, they soak up sweat, get heavy, and give an opponent something loose to grab that a rash guard doesn't offer.
What Can Wait
Compression spats, specific grappling shoes for certain gyms that allow them, and multiple rash guards for a full week of training are all reasonable purchases once you know you're sticking with the sport, but none of them are necessary for a first class. A single rash guard and a pair of proper grappling shorts is enough to show up prepared without overcommitting financially before you know if the sport is for you.
FAQ
Can I wear a regular t-shirt and shorts to my first no-gi class?
A rash guard is strongly preferred over a regular t-shirt, and shorts should be pocket-free and without zippers or belt loops, which most standard athletic shorts have.
Do I need grappling-specific shorts or can I use running shorts?
Grappling-specific shorts are designed without pockets, zippers, or hardware that can catch a finger during scrambles, which most running shorts aren't built to avoid.
Is it worth buying expensive no-gi gear before a first class?
Not necessary. A basic rash guard and simple grappling shorts are enough to start; more specialized gear can wait until you know you're continuing with the sport.