You and your friends were walking one day, talking and chatting... until they came upon a box, they tried opening it, cracking it, and even hacking it, but it refused to open... Since then, they have taken the box to the backyard and have tried to open it
Basically, there is no HP counter, it is your imagination. You must try to open the box by any means possible.
What you can do?
You can... 1- Use your imagination to directly attack it, as throw a nuke or punch it with fists of iron. 2- Use your imagination to indirectly attack it, like build a sentry turret or summon a dwarf. 3- Use your.... well... muscles to move it to any place you want, like a park or a spike factory. 4- Use your imagination to buff allies 5- Use your imagination to actually try and open it using something instead of destroying it.
And soon... you can start Raid Parties to try and destroy the box, debuff other parties, and destroy their buildings!