Among the pocket knives, few are so theatrical and exotic as the balisong. Also known as a butterfly knife, they are presented with a swift flick of the wrist, multi-directional jabs and twists, taking swipes at the air like a real menace. Carried in movies by greasers, Asian gangsters, Latinos, and bad guys of every stripe, it's a tool that announces low-class deadly intent with a flourish.
They're dangerous, occasionally illegal, and they are absolutely not toys. Which is a shame, because they're fun. The blade is lightweight, to be swung around in an arc, and the speeds that flick it open fast can quickly turn into a deep flesh wound on a careless user. Catching a finger between the blade and a closing handle can have a scissoring effect. Losing control of the knife while swinging it out turns it into a flying projectile. Slower fingers get pinched bloodlessly between the closing handles. Handling it wrong at all is a health risk. And there is the allure in figuring out how to wield it properly.
The blunted version, however, is ideal for playing around with. Find them by searching "dull" "practice" "trainer" etc. They're less expensive than a proper knife, and the whole joy of using them is just in the opening and closing of the blade. It satisfies a particular urge among pocket knife owners, which is to idly open the blade and close it repeatedly. The blade itself is duller than a butter knife. Blunt force is still a possible source of injury, but that's scrapes at worst. Unlike a real pocket knife, you don't feel bad for wearing it down from playing with it, since it's supposed to be entirely a toy.
The trick to handling them is as follows: always hold the safe handle. There are two handles, the safe one and the unsafe one. The unsafe handle is the one facing the balisong's sharp edge, and the safe facing the dull edge. No matter how you twist or turn with the knife, if you have a firm grip on the safe edge, the worse you'll get is a pinch. Then comes the three motions of opening the knife: flicking the handles apart, rotating the knife, and flicking the handles together. There's a momentum carried across the first two steps, which is reversed in the third. This can be done at any angle, but I find it feels best performed horizontally. The hardest part while starting out is getting your fingers in the right place to catch the unsafe handle while still having a solid grip on the safe handle. You have to keep a grip on a spinning blade using only the base of your thumb. Too late and the closing blade will jostle your loose grip, too early and you'll get pinched.
Next, it's very simple to make up balisong tricks: you simply extend the motions of opening the knife. Two flicks open the blade, three close it, four open it, and so forth. Throw in some fancy hand-transfers, maybe toss it in the air a bit, and you'll look like a proper 1970s movie goon ready to take a facepunch from the mullet-headed good guy. It's also good for people with restless hands; I've heard it described more than once as a "mall ninja's fidget spinner". A fine gift for anyone who likes to play with knives.