Q. How come many religious institutions offer bingos and sell raffle tickets, is that not a form of gambling?
A. As mentioned in the prior answer Remoh (Shulchan Aruch C.M. 370:3) writes that the accepted custom is that if someone has another established gainful occupation he is allowed to gamble.
However, Igrois Moishe (O.H. 4:35, E.H. 3:40) writes "playing cards or bingo (on a hall attached to a Shul), although there is no clear prohibition involved, they are considered repulsive wherever you play them and are like a "Moshav Letzim".
Rabbi Berel Wein (torah.org) writes: "Many rabbis opposed this type of fundraising activity, saying that holiness should not seek to find its support in basically unholy projects. However, the practicalities of the expenses of operating synagogues and especially schools soon overwhelmed any moral objections and Jewish sponsored "Bingo", raffles, and even Las Vegas nights became accepted practices in Jewish institutions in the United States and Canada. The objections raised to this type of fundraising have never disappeared. They have merely been ignored".
Bingos are not to be compared to raffles or lotteries. Peri Haaretz permitted the raffle of a Sefer Torah, when the scribe has difficulty selling it under certain conditions. Similar opinions are to be found in Pischey Teshuvo (Y.D. 270: 5), Divrey Malkiel (5: 147) and others.
Rav Poalim,(2:30) quotes Chavos Yoir (61) who allowed his students to raffle off a golden kiddush cup. He allows the raffle of a specific object, as opposed to money. The "Mifal Hapayis", Israel's lottery where the prize of the raffle is not a specific object but rather a percentage of the money raised from selling the draw tickets is the object of contemporary Poiskim debate. Yabia Omer (H.M. 7:6) prohibits while Tshuvos Vehanhogos (C.M.4: 311),Yaskil Avdi (Horav Ovadiah Hadia Zt"l, Y.D. 8:5) and many others permit.
Horav Shlomo Miller's Shlit"a opinion is that raffles and lotteries established by Gentiles are generally permitted. When promoted by Jewish institutions, if most of the monies raised are destined for Torah or Tzedoko organizations they are permitted, since one is in any case pleased to donate to them.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit"a