Here is a project I created for my group of ten year olds who have finished their course book. I wanted to teach them some modal verbs and I decided that this could be a good way of doing so.
The project is done over three or possibly four lessons, depending on the time you have. In the project, the children look at different board or card games, discuss the rules and learn about how to talk about permission and obligation, before going on to design and make their own game. I actually did something similar many years ago with a summer school class, but had forgotten all about it until I was wondering what to do with this particular group of ten-year-olds I am currently teaching. The project could also be suitable for CLIL teachers.
The full lesson plan is attached below in pdf form (google docs). You should be able to open and save it or print it out.