Excelsior

I was in Doom Gauntlet couple of times. And through this visits I participate in defeating all of its champs at least 10 times. But got no arties. Not even the small one So now I got some questions:
1. What the tricks?
2. How much dmg I must deal to get a chance for artifact to drop? Or any dmg will work?
3. Does the dmg dealt by pets counts?
4. What are the chances if I do everything right?
5. And does the luck (game stat) affects this chances?

1 ) no trick
2) any damage will work.
3) yes damage dealt by pets count.
4) you could do everything right but artie drops are rare.
5) Good question no one knows.

i know this didn't help much but it's the truth. just gotta grind away in there.

Thanks for info.