From Pierson’s Inferno dance to liquor-treating in the residential colleges, to the traditional Yale Symphony Orchestra concert in Woolsey Hall, this Halloween weekend was full of revelry — but it was not without rules.

Safety was a driving force behind Yale officials’ plans for Halloween festivities this weekend, as they struggled to control alcohol consumption and overcrowding at social functions. Residential college masters and deans reminded students to celebrate responsibly and reiterated Yale College’s regulations on social functions and drinking. But there was little they could do to prevent large parties and the practice of liquor-treating — where several suites in a college sign up to host students and provide a signature drink instead of candy — which students hosted in at least seven colleges.

Some residential colleges took a hard line. Stephen Pitti GRD ’91, master of Ezra Stiles College, sent an e-mail to all Stilesians Saturday afternoon that specifically banned liquor treating. Stilesians seem to have complied — two Stiles residents interviewed said there was no liquor treating in the college. Pitti and the masters of Branford and Silliman colleges banned large parties as well, with less success.

Three Branford students said liquor-treating persisted in the college in spite of the large party ban. Other colleges that engaged in liquor-treating include Davenport, Jonathan Edwards, Timothy Dwight, Berkeley, Saybrook and Morse, according to students from each of these colleges.

But instead of bans, some college masters tried a gentler approach to preventing excessive drinking during the holiday weekend.

In an e-mail to Saybrugians Friday morning, Saybrook College Master Paul Hudak reminded students to “be sure to take care of each other,” acknowledging that “lots of partying will surely be the norm” over Halloween weekend. In an e-mail to the News Sunday, Hudak said he didn’t feel it was necessary to remind students that liquor-treating is illegal.

“I think they understand the reasons, and the dangers involved,” Hudak said. “I hope that they comply with the rules.”

Timothy Dwight College Master Jeff Brenzel said he also sent a note to students “encouraging mindful decisions and considerations of safety and mutual respect.”

Penelope Laurans, master of Jonathan Edwards College, organized many alcohol-free, Halloween-themed activities over the course of the weekend, including pumpkin carving in the JE courtyard and a screening of “Rocky Horror Picture Show” in the college dining hall.

Jesse Hassinger ’11, chair of the Silliman Activities and Administrative Committee, Natalie Papillion ’13, a co-chair of the Calhoun Student Activities Committee and Laura Kling ’12, a co-chair of the Pierson Student Activities Committee, all said that liquor-treating had never occurred in their colleges during their time at Yale. While Pierson may not have hosted liquor-treating, it did sponsor the Inferno, an annual dance party open to all undergraduates. No alcohol was served at the party, which Kling said more than 1,000 people attended.

“With an event this big, with a holiday as crazy as Halloween, our responsibility is to make Inferno as safe as we can,” said M.C. Miller ’11, a co-chair of the Pierson SAC.

To combat overcrowding this year, Miller said the dance was formally opened to the courtyard instead of being confined to the dining hall alone. Speakers were placed outdoors to ease crowd flow, Kling said, resulting in shorter lines for students entering the party than in previous years. Miller estimated that eight to ten Yale police officers were on hand for the event, in addition to a Yale fire marshal. Kling said one attendee was transported off-site for medical care, but said she did not know why the student needed care of if the student was taken to Yale HEALTH or to Yale-New Haven Hospital for treatment.

Halloween weekend was capped off by the Yale Symphony Orchestra’s annual concert, which started at midnight on Halloween. YSO Social Chair Julia Pucci ’13 said it is “quasi-lamentable” that Halloween falls on a Sunday this year, but Pucci said YSO members were still planning to approach the show with the same “verve” as it would in any other year.

In response to rumors that YSO musicians perform while intoxicated for the Halloween concert, Pucci said she expected some pre-show drinking. The YSO discourages musicians from “pre-gaming” the concert, said Pucci, who planned to abstain herself.

“I find the concept of being inebriated while playing my instrument terrifying,” said Pucci, a violist.