Children may not play soccer, football, baseball, or basketball on Shabbat. Since adults make a big deal out of these games and they have intricate rules and procedures, they are prohibited, as they are considered a prohibited weekday activity. Besides, sometimes these games involve additional prohibited activities, such as preparing the field for a game, driving to the field, registering for the game, and buying and selling tickets or team merchandise. It is also prohibited to watch a soccer or basketball game on Shabbat, because this is a weekday activity. It is even prohibited to play with the balls associated with these sports at home or in a yard, because they are muktzeh and because it is a weekday activity. For the same reasons, all of the above applies to tennis as well.
Children may play and run around for their enjoyment but may not participate in exercise classes (see above 22:8).
Children may play with balls designed for young children, on condition that they play indoors or in a paved yard. However, they may not play on grass or on a dirt yard, out of concern that they will level the ground. They may play table tennis for fun, since that is generally played indoors. There is no need to worry that by allowing children to play with balls at a young age, they will get used to it and will continue doing so as adults, since the permission is limited to balls designed for children, which in any case adults do not play with.
One may not recover a ball from a tree using one’s hand or a stick, as it might lead to breaking a branch. If the ball fell out on its own, one may play with it (19:7 above; SSK 16:8).
. Some prohibit playing soccer and basketball on Shabbat out of concern that people will end up leveling the ground, similar to what appears in SA 338:5 and MB 308:155. Others forbid these games out of concern that the players will end up fixing the ball or inflating it (Ketzot Ha-shulĥan). In any case, the rabbinic consensus is that one may not play soccer or basketball on Shabbat. It would seem that the primary reason is that it is a weekday activity (which is also the reason behind the prohibition to ride bicycles). This prohibition should not be taken lightly, as it is rooted in the Torah. Any activity that is burdensome and taxing serves to destroy the peace and rest of Shabbat, and is prohibited by Torah law (Ramban on Vayikra 23:24). The book of Yeshayahu elaborates upon this: “If you refrain from trampling the Shabbat, from pursuing your affairs on My holy day; if you call Shabbat ‘delight,’ the Lord’s holy [day] ‘honored’; and if you honor it, and not go in your own way, nor look to your affairs, nor speak of them” (Yeshayahu 58:13). The Sages elaborated further: “‘Not go in your own way’ – the way you walk on Shabbat should not be like the way you walk on weekdays…. ‘Nor speak of them’ – your speech on Shabbat should not be like your speech on weekdays. Speaking [about mundane matters] is forbidden, but thinking about them is permitted” (Shabbat 113a). Since soccer games and basketball games involve a big production, have intricate rules and regulations, and are taken very seriously by many people (some even make their living playing these sports), they are the ultimate weekday activity. The leniency for children to run for enjoyment is limited to running around freely, not in the organized framework of a sport or exercise. Rav Kook presents this approach in Oraĥ Mishpat §152.