LessWrong Community Weekend 2026 - Applications are open

The LessWrong community, a hub for rationalist and effective altruism discourse, has officially opened applications for its 13th annual Community Weekend (LWCW), scheduled for September 11-14, 2026, in Berlin. The event, described as one of the world's largest rationalist social gatherings, will take over the Youth Hostel Wannsee to host over 250 attendees from across Europe and beyond. Organizers note the event is 'AI-inspired by Harry Potter and the Methods of Rationality,' blending themes of logic and narrative. The core format is an 'unconference,' where a digital schedule is populated with 100+ workshops, talks, and activities proposed by the attendees themselves shortly before and during the event.

The volunteer-organized, non-profit event is priced on a sliding scale from €225 to €275 for a regular ticket, which includes hostel accommodation, all meals, and snacks. Supporter tickets at €300+ help fund financial aid for those who need it, as the organizing team is unpaid. Applications opened April 4, with acceptance letters going out starting May 1. The gathering emphasizes creating a diverse, family and LGBTQIA+ friendly environment centered on three pillars: curiosity for truthful understanding, passion for effective personal and human goals, and caring for empathetic relationships. Past attendees have called it their 'favourite weekend of the entire year.'