Board Thread:Questions and Answers/@comment-26051043-20150128033829/@comment-24577221-20150128041318

The chance of getting a Ghazt from Entbrat + T-Rox is 1% per try, with no torches. So it's not surprising that you haven't got one yet; after 70 tries, you'd have a 50% chance of getting at least one (as these kinds of statistics work).

We're still working on finding out how much effect the torches have, but so far, it looks like having one torch lit increases the chance of success for that combination to about 2%. It's still not high, but 2% is twice as high as 1%.