well I just watched it and I was shocked at how they did their shared dreams it was the same way I thought of to have shared dreams get the dreamers to connect to each other with a wire *mine was to monitor the brain waves that is the dream and link them together to form one complete dream sequence* and thats what they did but it was at their wrists, it was amazing in the end they had like 6 dreams in one they went deeper and deeper just to implant a notion, and the act of doing that s inception it was amazing I learned/made up a new reality check a totem a unique object that is simply unique to you like the main characters is a spin top and for him he spins it if it topples then he isn't dreaming if it doesn't then he is omg, If u haven't seen this movie you must.