(CNN) It's an event where you might find Hannibal Lecter sitting near six Yodas, while Trekkies line up in the drinks queue along with Scooby-Doo.
Fancy dress had appeared to be off the menu for this weekend's London Sevens after problems with fans' behavior last year, but organizers now say the expected 70,000 spectators can wear what they want at Twickenham, the home of England Rugby.
However, spectators have been warned to act sensibly following complaints from local residents -- who have been allocated an extra 5,000 tickets this year -- in the wake of the 2015 antics.
One resident, Jen Ruby Sargaison, was quoted as saying: "I had the misfortune of walking through Twickenham center at about 7 p.m. on Saturday and saw numerous men urinating in the street, literally just in the middle of the pavement, litter ankle deep, vomit everywhere and people throwing beer at bystanders.
"On what other day can you urinate in front of a policeman and not be fined or arrested."
Colorful costumes are a big part of the multi-city Sevens World Series, which counts the Hong Kong tournament as rugby's biggest party.
While dressing like Darth Vadar or Buzz Lightyear is allowed in the UK capital this time, it is not being actively encouraged.
A spokesperson for the Rugby Football Union said: "Fancy dress is not banned for this year's event, it just isn't being actively promoted as this event's theme this year."
Despite the go ahead to dress as you see fit, the RFU has, however, introduced a new set of drinking restrictions never seen at the World Cup or Six Nations matches it has hosted.
The bars will open at noon and close again between 3-5 p.m. at the discretion of the RFU, Richmond Council and the Metropolitan Police over both days of action.
There is no suggestion that drinking restrictions will come into play for other matches at the venue after this weekend, with the RFU spokesperson saying "these restrictions are different to any other rugby fixture that has taken place at Twickenham."
Instead of fancy dress, this year's theme is a "Feast of Rugby" -- in collaboration with street food organization Urban Food Fest -- aimed at creating a more family-friendly event.
"The purpose of these changes is to ensure the event is enjoyable for ticket-holders and members of the local community, to bring the focus of the event back to the rugby and to ensure that the new theme is reflective of the family-friendly ethos of the weekend," the RFU spokesperson added.
There will be a maximum of 35,000 attendees per day, with a no re-entry policy for the first time at London Sevens -- a policy that was implemented at the Rugby World Cup and has also been in place in the past for music concerts at Twickenham Stadium.
The move has been welcome by Richmond Council, which has been working with the RFU and the police to address last year's problems.
"There was very little anti-social behavior at the World Cup but London Sevens was different last year," councillor Pamela Fleming told CNN. "I remember traveling on a train that day and people were already very drunk by two in the afternoon.
"It's traditionally been a family event but last year the mistake was made in the marketing, pushing forward the fancy dress theme. I don't normally get complaints from the rugby at Twickenham but after London Sevens last year the number of complaints were massive.
"It was a genuine problem rather than people just being silly. This wasn't just high spirits, it was exceptionally bad. Thankfully, the RFU have reacted very well and promptly to what happened last year."
The United States was a shock victor in the 2015 final, beating Australia.
Fiji has a 14-point lead in the 2015-16 series, despite a surprise defeat by Samoa in last weekend's Paris Sevens final.
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