Undying has some of the greatest single player fighting in the business. In addition to having the multi-function weapons and an inventory of miscellaneous usable items we've all come to expect in an FPS game, you also have powerful spells. You can stockpile health-boosting items and your character will automatically use them as needed. This makes battles more a matter of surviving the actual fight rather than a drawn-out war of attrition. You equip a weapon in your left hand and a spell in your right hand at all times.
Weapons usually have two attack modes, and some have variable ammunition.
There are even some odd combination effects between certain weapons and spells. Guns have to be reloaded and although your spell power refreshes quickly, it drains quickly too. You typically need to use a combination of spell power and old-fashioned bullets in every combat. Most enemies can be taken out by a single, well-aimed shot, so your initial weapon, the revolver actually stays useful throughout the entire game. Besides fighting, you also do some light puzzle solving, much of which is optional.