The basic concept is thus--magical items are powerful, unique, and rely upon their own innate power, but also upon the power of the connection between themselves and the individual wielding them. Therefore, you cannot tap into the greater powers of a magical item when you pick it up. It is not an on-off switch. The sword does not gain its max +10 damage effect as soon as you touch it. Instead, you must learn about it, complete quests with it, and generally invest time, energy, blood and sweat in order to gain its greater powers.
This concept probably works best with pen and paper role playing games, but it is an idea that the design team at Trese Brothers Software is working on bringing into Secrets of Steel. What do you think? It means the legendary magical items you find in the world will start at less than their full potential--but you can watch them grow into their true might. It may mean that quests are required to forward their growth, and that you cannot easily shift powerful, magical equipment around between characters whenever you want. But, for me, the results have always been a more powerful sense of achievement and self for the characters who has decided to carry the burden of these immensely powerful item, and who has bled to take them to it to its highest potential. As a gamer--where does your heart lie?