Box Physics!

I finaly made it so when my character moves into the cube the cube moves as if it were being pushed!
But i have a big problem!
I need to make it so when the bullet that my character shoots collides with the box that the box just changes to a different object now when i go to the sensors and add a collison sensor it asks for a Property as in Property does that mean object. How can i find the property of an object?

you can add properties to any objects as you like. btw, i don’t fully understand your question. i assume you add a collision sensor to the box (or bullet), and the property field is an option to filter only specific collisions. so to filter the bullet, simply apply a property to the bullet called “its_me” or “i_hit_you” or “bullet” and type this in the property field of the box’ collision sensor.

if u want i would make you a demo of that send me a pm if you do.