Basics of moving and using weapons | Controls DayZ - ArmA 2 mod Guide

If you haven't ever played ArmA 2, I'd suggest completing the two basic training mission on the single player mode (E01 and E03). No description can fully express the rather specific control that you have over your character and inventory. It's better to do it in controlled conditions than when fighting with zombies in DayZ. If you feel you don't have smoothness in overcoming obstacles and quickly managing your equipment, keep repeating the training mission to get better. Believe me, when a band of Zeds or a bandit (other player) catches up with you, each mistake you make can cost you your life.