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I believe he means Shield Slam, and yes anyone using a 1 hand and shield can do so (although the DK has skills that increase it's damage). To perform a shield slam, hold block (RMB), then attack (LMB) and you will bash with your shield and do a small amount of damage (You can even see this animation when not in combat). Hope this helps.
Sorry was talking about on the website for verification. Look through your class skills I believe and it could possibly have it in there, but if not just browse around your skills and you will find it I am sure.
Any class can interrupt an enemy skill - press both mouse buttons together while the enemy is winding up a big attack. This stops the attack and leaves the enemy dazed for a few seconds, at which point you can follow up with a heavy melee attack (hold down left mouse button)