Topple Cover is a new Combat Action. It is a half action that lets you change the orientation of cover if possible.
Light pieces of cover (eg. wood tables) are a simple half-action with no checks.
Heavy pieces of cover (eg. bookshelf full of books) require a strength test. The difficulty of this test is determined by the weight of the object vs. the number of people pushing it over.
-A failed test means the object reorients as desired, but the action counts as a full action instead.
-A test failed by 3 or more degrees means the object doesn’t move at all, and you must take a toughness test, or be winded for one round (the next round you only have a half action).
Upon toppling cover over, you are assumed to be behind it, and still have a half-action remaining to use as you wish provided you pass the check without failing.