HEPscape: an escape room about high energy physics F. Cavallari1, P. Astone1, M. Bauce1, M. Campana1, S. Dall’Osso1, E. Di Marco1, M. Drago1,2, L. Fantini1,2, S. Mariottini1,2, G. Padovano1,2, R. Paramatti1,2, G. Pisegna1,2, S. Porzio1,2, L. Roberti1,2, C. Rovelli1, L. Soffi1, R. Tramontano1,2 Abstract Escape rooms are more and more popular nowadays. They have the challenges of a treasure hunt and represent a pleasant way to encourage team building. In addition they are a fun way to discover a new subject, a key point that can be exploited for science outreach. In 2021 a team from INFN has built an escape room about high energy physics, called HEPScape. The visitors have the impression of visiting the Large Hadron Collider at CERN and of entering one of the experimental control rooms. It makes use of projectors and posters which replicate the control room environment. Through some clues, that are hidden in the room, the visitors discover the purpose of particle accelerators and high energy physics experiments. The games can be tuned to the age group, resulting in a fun experience for everybody. HEPScape is made of portable equipment that can be transported and assembled in less than two hours. This allows to use it in science fairs and exhibitions. In addition it can be brought on demand to high schools in remote provinces. The material and the format of the games are simple and it is possible to replicate and translate the games in other languages. Feedback and experience from two science fairs is presented. Keywords High Energy Physics, Outreach, Escape room Introduction In contemporary world, teaching methods have not evolved as fast as the new communication methods that the young generations adopt. The perception that the students may have of old-fashioned frontal lessons is therefore not enthusiastic, particularly for what concerns scientific subjects. New teaching methods that make use of active discovery of the subjects may help stimulate the curiosity of the students, and convey the idea that studying scientific subjects is fun. Since a few years escape rooms have become very popular in most cities. An escape room is like a treasure hunt in a closed room. The team must solve a series of puzzles and quizzes within a given amount of time, in order to open the room door and escape from the site. The activity is often guided by an external moderator who helps the team from outside to find the clues hidden in the room and solve them in time. Escape rooms are so intriguing and fun that they are also often used by adult co-workers as a team building exercise. Usually the room has an underlying theme and decoration: ancient history, detective story, crimes eccetera. In the past few years escape rooms were adopted by few teachers as an unconventional method to teach a new subject through active discovery, see for example [2] and references therein. For the initial overview of a subject they have proven to be very effective. This fact can be exploited for science outreach. In 2019 a team proposed an escape room to the Open Day visitors. In 2020 a similar attempt was made by a team from the CMS experiment for a high school student internship. In 2021 a group from INFN Rome put up an escape room, named HEPscape [1], and brought it to two science festivals in Italy with great success, as explained in this paper. More than 1100 visitors participated in the activity in Rome and Genova. Escape room setup HEPscape can be installed outdoor in a gazebo or indoor in an adequate room. The required space is about 25 m2. The visitors are welcomed outside the room, they are given a helmet and they are told that they are going to visit the LHC, the largest particle accelerator in the world, which is located in an underground tunnel. The door of the escape room is made with a PVC curtain showing the image of the LHC tunnel. Inside the room there are many posters hanging on the walls, showing photos of the LHC and its experiments, as well as som