Answer: There is a big difference between Clics and Magna Tiles. The question of Boneh only comes into play if the pieces are actually connected together and don’t come apart easily. Therefore, Clics and Legos might be a problem while Magna Tiles and Kapla (wooden building blocks) have no issue whatsoever.
Question: Okay, so can someone build with Clics on Shabbos?
Answer: There are definitely reasons to be lenient about your kids building with these types of toys. R’ Shlomo Zalman, R’ Moshe Feinstein, and others permit these types of building toys where constructing and destructing are the main usage of the toy and whatever was built is so temporary it doesn’t even fall under the category of Boneh. However, there are halachic authorities including R’ Eliyashiv who are stringent.
Question: If my kid asks me to help him build something with Clics, can I help him?
Answer: That is a lot harder to allow. The Shmiras Shabbos K’Hilchasa uses the lashon: אין למנוע את הילדים מלבנות וכו’”, “you don’t have to stop your kids from building.” This signifies that this heter is not so foolproof, and that there is merit to putting these toys away and not letting your kids play with them on Shabbos. With that said, anyone who relies on R’ Moshe or R’ Shlomo Zalman should rely on them for their kids, but they should not partake in the building themselves. Magna Tiles, on the other hand, have no issue and you can help your kids build with them.
Boneh, another one of the 39 melachos on Shabbos, can be categorized as follows. Firstly, there is the regular Boneh which is the assembling or building of a structure that is attached to the ground. Any part of the process of making a structure like the creating of a foundation, the building of a wall, the building of a roof on the walls, etc., are all included in the melacha. This means that not only would putting missing bricks into a wall or fixing a hole in the roof fall under the prohibition of Boneh, but even smoothing out dirt on the ground (which creates a foundation) is forbidden.
The second category is called Boneh b’Kaylim, building in regard to objects. Although it is a matter of dispute, the Shulchan Aruch rules that Boneh exists even in regard to objects which are not actual buildings. That means that any creating or fixing of an object can be a problem of Boneh. There are some exceptions, but the rule of thumb is that if pieces are being put together in a way that is strong and will last for a significant amount of time, then is a problem of Boneh. For example, if the screw fell out of someone’s glasses, they would not be allowed to put it back in. This is because by screwing them together they would be creating the pair of in a secure and lasting way.