I also should point out that sometimes people cheat when they have a chance to get loot. They can save the game and keep reloading until they get what item they want..
You could kind of get around this by using a seeded random number. When the player starts a character, new game or area, seed a random number generator. Then use this random number generator for your loot generator every time you need a loot reward. The player can load the save game as much as they like, the same 'random' number comes out of the generator each time. The only way they can change the outcome is by going back to where the seed was randomised for the generator in the first place.
Of course, as you are saving a characters progress they could open the save file and change things there. You could implement a simple checksum to prevent casual tampering. The bottom line is, unless you do calculations and store data server side, people can cheat. I wouldnt worry about it. Have fun developing your game and worry about that stuff afterwards if its a major concern.