I am asking a follow up question on a response to "Building" a gameboard on Shabbos. ON 25 Cheshvan 5765 Rav Ro’i Margalit responded: According to the Shulchan Aruch (313:6) it is forbidden even though it isn’t meant to last for a long time, because the legs fit exactly into place. Achronim wrote that it is best to follow the last opinion brought there - not to permit it unless it is a vital need for Shabbat. Hence the solution would be to put it together, but not take it apart until Shabbat is over, this also seems to be the opinion of the Shemirat Shabbat Kehilchata. My question is : The M"B (45) quotes M"A and T"Z as permitting bottle caps designed to open and close constantly. Although these boards are not meant to "open and close constantly" but the "derech shimush" is to assemble, play, and disassemble. This seems to be more comparable to the bottle cap case than the bed/cup case which might last for longer (for the stay at the new place in the case of the bed, for constant drinking until the need for collapsing). I assume the Rav’s reference to SS"C is concerning lego which he prohibits in the text itself (16:19) new edition, even though, GRSZ"A suggests l’kula in the footnote (59) based on the comparison to caps. In halacha 20, SS"C prohibits assembly of kits (planes, etc.) implying it is only prohibited because it is "normal to build them for many days." Had it been the norm to assemble, play, disassemble always, lan"d the implication is it would be comparable to caps. The stringency regarding Lego it seems lan"d is that it is often left for several days before being disassembled. Also I am confused about the reference to the second opinion in S"A regarding cups. The M"B seems to imply that the stringency regarding cups is that even though the connection is "rafui" but it is normal to connect them "m’hudak". If one actually does fasten "m’hudak" as might be the case with the Rummikub tablet, and, if we assume that it is not comparable to bottle caps, shouldn’t this be prohibited according to both opinions in the S"A. Thank you in advance for your response. B’chavod Rav, Yakov Haber P.S. If the Rav wishes he could respond in Hebrew.

You have indeed shown an understanding of the issues involved of Boneh ,therefore I can refer you to further sources which will enrich your knowledge and show other aspects.(See שו"ת חת"ם סופר סי' ע"ב, ציץ אליעזר חי"ג סי' מ"ו, יחווה דעת ח"ב סי' נה) You may also see an abundance of material in the Hebrew counterpart of this website and I'm sure in other places as well. However, the nature of this column dictates to us to be short and concise in order for us to answer the many questions of others as well. Therefore, in regard to the specific question of the inserting legs of the game board, Rabbi Margalit in his answer followed the opinion of the Shmirat Shabbat Kehilchta based on the psak of Rav Shlomo Zalman Oirbach zt"l (and others), who were stringent in this matter. However, Rav Valdenberg zt"l in the above source in the Tzitz Eliezer 13, and Rav Ovadia yosef shllit"a, in the above source in Yechaveh Daat 2:56, were lenient in regard to assembling and disassembling a "kli" which is not strongly connected and is not meant to remain assembled which applies to the game board situation.