Food is crucial; characters will starve if not fed regularly. Purchase food from vendors or hunt animals. Healing requires bandages, which can be bought or crafted. Apply bandages to injured body parts via the character panel. Stealth (C key) allows you to sneak past enemies or pickpocket. Be aware of your 'Stealth' skill level and line of sight. Resting in a bed or sleeping bag accelerates healing. Always carry extra food and bandages!
