The serve is one of the key fundamental components of a game of ping pong. If you want to oversimplify things, there are only really two things you need to know to play: how to serve, and how to hit the ball back.
In a friendly match, things are likely a bit looser (unless the both of you are real enthusiasts), and a serve is little more than tossing the ball and whacking it with your paddle.
But in an official match, you’ll need to be a lot more specific. There are a surprising number of table tennis serve rules, some that are very easy to run afoul of if you’re not paying very close attention to your every move.
So, let’s go over, in detail, the seven (really six) rule you need to throw a tournament legal ping pong serve. Rather than simply regurgitate the rules exactly as stated in the ITTF handbook, I’ll restate them with less “legalese”.
you need to put the ball in your outstretched hand (the one without the paddle; the left hand for most players), and hold it there without moving for a moment. The hand needs to be fully stretched (not curled).
Toss the ball as straight up as you possibly can (minimal lateral movement) at least 16 cm (or about 6 and 1/3 inches) into the air. There’s no other stipulation on height, so feel free to toss it as high as you feel comfortable; there is likely no maximum height so as not to disadvantage taller players for no reason.
You need to then hit the ball before it touches anything else. This does technically put a BIT of a maximum on how high you can throw (it can’t impact the ceiling or a light or something before being hit) but that’s not exactly much of a restriction.
Hit the ball pretty much however you like. However, some restrictions are important to keep in mind so that you’ll know how to score in the game.
First, the ball must impact your side of the table before anything else. You can’t just spike the ball onto your opponent’s side immediately.
Second, after bouncing on your side, the ball also needs to touch down on your opponent’s side of the court; you likewise can’t try to simply have it impact your side and then bounce out of bounds on your opponent. The ball also needs to get over the net.
A note for doubles: rather than the whole court being valid, only the right side is here.
Until you hit the ball, it needs to be perfectly visible to the opponent. This has a few components.
Not only can you not deliberately hide the ball at any point during the serve (throwing it behind the back, leading it with your paddle to obscure its exact position, etc.) it must also stay above the level of the playing field; it can’t go below the table in other words for tricky popups.
This stipulation applies to both the server and their doubles partner in such a match, by the way, so no funny business there.
This is a pretty simple one. Once you pop the ball up, you need to immediately get your arm and hand out of the way. At no point after the ball leaves your hand is it allowed to be between the net and the ball, likely as an extension of the “don’t hide the ball” clause above. It also helps stop embarrassing flubs where you foul your own ball with your arm, so that’s nice.
This is what I like to call the “personal responsibility clause”, and it’s one of the vaguest rules here.
Basically, the players, not just the umpire, are responsible for ensuring that a serve is legal. If you’re not sure whether you did it right or not, it may be best to call foul on yourself to prevent any punitive action being taken, like being given a warning by the umpire.
This is important, as a warning given for an illegal serve impacts the game going forward in a big way; your benefit of the doubt is pretty much completely gone at that point, and any suspect serves from then onward are simply declared incorrect automatically. This goes for both players in a doubles match, regardless of which player was warned.
Another very simple one. Essentially, this is the rule that an umpire can waive any of the above rules, or at least relax the specifics, if some physical disability is preventing the player from actually being able to perform any of them. Experienced players know that the rules can change, so it’s important to adapt.
A quick example of this would be a player with limited mobility in their left hand; if they physically cannot straighten their fingers all the way, that restriction on rule 1 may be waived by the umpire. Some rules in Para Table Tennis can even be applied. A more extreme example might be a one-armed player who has nonetheless figured out a way to play the game well that fits with their disability; obviously the restriction of serving with their “free hand” is impossible to fulfill.
These rules are fairly simple on paper, but can give many players trouble in actual practice, the two big ones being the rule on how high you need to toss the ball, and the rule on hiding the ball.
A mistake many beginners make is either not tossing the ball high enough, or not waiting for it to begin descending again; they essentially just toss the ball into their waiting paddle and whack it. This would be illegal in an ITTF match.
Likewise, the rule against hiding the ball is often broken, though this time more intentionally; one of those rules that it’s difficult for umpires to properly enforce because they simply don’t have the same perspective as the other player. Sneaky players will often hide the ball intentionally, if only for a moment, to gain advantage since it’s difficult to call them on it.