I'm new to the concept of unique variants, and somebody told me that if I ever get a bad UV I should reroll, but he didn't explain what is that..
could anyone here please explain me what is "reroll"?
Unique Variants... reroll?
You guys need to keep some stuff secret. You may not realize this, but what sandwich said was just an epic fail. Now stand in attention.
See the wiki page "Unique Variant" to learn more. UVs can come from crafting or from Punch. In either case, they are random, like rolling dice. That's why people talk about "rolling". Some UVs are so weak as to be useless --- for example, Damage Bonus Low against Slimes, on a piercing weapon that you would never use on slimes. There is no point in keeping such a UV, if you have any chance at a better one.
Suppose that you have this UV on a 3-star item. When you upgrade to 4 stars, uncheck the "keep UV" box, in the hopes of getting a better UV. You have only a 10% chance (roughly) of getting a UV, but if you do, then it will probably be better than the one you gave up, and may even be great. And you get another chance when you upgrade to 5 stars.
Similarly, if you got this UV from Punch, and you have another 20,000 crowns to spend on him, then consider trying for another UV, because this one is worthless.
Just to be clear, UV's are not 'random' - while the type of UV chosen is probably random, the magnitude is definitely not. It is weighted towards lower values.
That's an important point, that small UVs occur more often than large ones. When Anzeis re-rolls, he will probably get another Low UV (if he gets one at all).
To clarify the terminology: The magnitude is random, but it is not uniformly random. In contrast, the type of UV is random, and moreover it seems to be uniform.
Oftentimes, it might seem like the random number generator hates you; I got Gremlin VH, then Gremlin Med on my Combuster.
Reroll? http://www.youtube.com/watch?v=oHg5SJYRHA0
Did I get that right?
It means to get a different UV from Punch, the Gremlin in Haven Bazaar. It's like gambling; you end up with something random, and if you don't like it you try again. But it costs quite a bit; it's not advised to roll until you're a Vanguard/have stupidly high amounts of money from some epic market selling or something.