Fifteen pages for the first week with a net. How to put it up, how hard the ball should be, how the game works, and the arguments you are about to have with whoever you are playing against.
Roundnet is a 2v2 sport played around a small circular net on the ground, by 4 players. Your team gets up to three touches to put the ball back onto the net, and once the serve is away there are no sides and no boundaries: all four players move wherever they need to.
Two against two around a circular net. The four of you stand 90 degrees apart. One player serves the ball off the net at the opponent standing directly opposite. That team has up to three touches to put the ball back onto the net, then it is the other team's turn. Whoever wins the rally wins the point.
Two teams of two, a circular net, three touches per team alternating between partners, and rally scoring to 15 or 21 with a two point margin. Below is the whole ruleset in summary, in the order the IRF document uses, with the detail pages linked from each section.
Every rally is a point, no matter who served. Games run to 15 or 21 depending on what you agreed before you started, and you have to win by two. A match is usually best of three games.
Nobody decides, because there is no referee at any level of this sport. Players call their own violations immediately, and when the two teams cannot agree, the rules say replay the point. That is the written answer, not a friendly compromise.
The rally ends when the ball hits the ground, when its first contact with the set is the rim or the legs, when it bounces on the net more than once, or when it never comes back off the net at all. Everything else is still live, including two shots that look illegal and are not.
Three, and they must alternate between the two players. The same player may not hit the ball twice in a row, apart from one specific exception. The standard pattern is receive, set, hit.
Officially four: two against two, standing 90 degrees apart around the net. That is the only format in the rulebook and the only one played at tournaments. In practice a net works with any number from two upwards, and the formats people use for that are below.
Push the rim sections into a circle, fit a leg at every joint, flip it over, hook the net on at four opposite points and then tighten it evenly. The whole thing takes two minutes. The tension is the only part that is easy to get wrong, and it decides whether the game is any fun.
Softer than you think. The IRF rules put a roundnet ball between 2000 and 3500 pascals, which is 0.3 to 0.5 PSI. Inflate it until it holds a round shape and still gives clearly when you press hard with a thumb. If it feels like a tennis ball, let air out.
Measure it. A regulation set is 91.4 cm across at the top and 20.3 cm high, and its net is tensioned so a ball dropped from 1.5 m bounces back around 50 cm. Match those three and you have a proper set, whatever the box said.
Rally without scoring, play winners-stay-on with a crowd, one against one with two touches, two against one, unlimited touches for longer rallies, or catch and throw for teaching positioning. None of it is official, and all of it works.
Grass, sand, a sports hall floor or packed dirt. Anywhere flat with room to move around the net. The regulation court is a circle 8.5 m out from the net in every direction, about 17 m across, and your garden is almost certainly smaller than that. It does not matter.
Start by letting air out of the ball, then drop the three touch limit, allow a catch, serve gently underhand and count rallies instead of points. Add the real rules back one at a time, and only once the current version has become easy.
Casual play, not really. It carries about the same risk as any garden ball game. The risk goes up when people start diving, which happens sooner than beginners expect, and the surface you chose decides how much that costs.
Roundnet ist ein 2-gegen-2-Sport, gespielt von 4 Leuten um ein kleines rundes Netz am Boden. Dein Team hat bis zu drei Ballberührungen, um den Ball zurück auf das Netz zu bringen, und sobald aufgeschlagen ist, gibt es keine Seiten und keine Feldgrenzen: alle vier bewegen sich dorthin, wo sie hinmüssen.