It is not hard to find knock-offs and fakes in our world: purses, watches, movies, snake-oil medicine, Go-Bots and the Family Guy. It stands to reason that a fantasy world where magic is at least known to exist, there would be fake and knockoff magical items. These sorts of items could be sold by charlatans, honest merchants who don't know any better, or even easily availables alternatives for those who can't afford the real thing.
Knock-Off Magic Item Chart
Works the same as the regular item. May appear cheap or oddly coloured. GM rolls d12 and does not share result with the player.
1 Item doesn't work at all
2 Works 10% of the time
3 Works 25% of the time
4 Works 50% of the time
5 Works 75% of the time
6 Works d4 times before failing for good
7 Works d6 times before failing for good
8 Works d10 times before failing for good
9 Works d12 times before failing for good
10 Works d20 times before failing for good
11 Works better than original, added effect or power bonus.
12 Item is cursed!