Creating instances of an object to make physics simulation.

ctrl+c, ctrl+v copies object
ctrl+d duplicates
??? makes instance

How to create instance of an object?
so many objects change when I change one of them

I know there is group instance, but when i tried it out objects aren’t working in bullet animation…

ctrl+d duplicates
The default shortcut is Shift+D to duplicate. Alt+D creates a linked duplicate

If you want to copy rigid body settings from one objet to another you vans use the options in the toolshelf


But duplicates do not react like instances. If I change duplicated object(for example in edit mode) only that object changes I need to make INSTANCES of object.

Duplicate your objects. Then select all of them and hit ctrl+L for link. Choose link object data.