Use Class D2 (Assembly and leisure) relate to cinemas, music and concert halls, bingo and dance halls (but not night clubs), swimming baths, skating rinks, gymnasiums or area for indoor or outdoor sports and recreations (except for motor sports, or where firearms are used).
Use Class D2 (Assembly and leisure) can benefit from limited permitted development opportunities to change use without requiring a full planning application. There may be conditions and limitations to such a change however, and further detailed information about this can be found here on the Planning Portal website. This website also details other restrictions to permitted development that may be in place, such as planning conditions or Article 4 Directions, and it is recommended you get confirmation from the local planning authority about changes of use proposed using permitted development rights.
If a D2 premises does not benefit from permitted development rights, planning permission may be sought to change it to another use. You can learn more about this process here.