by Durst » Wed May 28, 2014 3:56 pm
For chapters 3 and up, every single level has a maximum of 5+1 chests. Never less. It will be 8+1 if the area is marked with a "drop rate x1.5" notation. Those numbers are static and do not change for any situation. You either get 5+1 or 8+1. It doesn't matter how you go through the level or what team you use or how long you wait on the last wave or how quickly you get there. If you enter the stage without the "drop rate x1.5" notation, you will get 5+1 chests. If the notation is there, you'll get 8+1.
Which chests you get (brown vs. gold) is determined at the beginning of the level, as soon as you enter it. The game decides how many chests will be brown and how many gold, and all you have to do is keep spinning the wheel until all the chests show up. Assuming you enter during a 5+1 section, the game might decide that you are going to get 4 brown chests and a gold chest, plus another brown from the boss. In all likelihood, you will relatively quickly pick up 4 brown chests, then spend a while spinning your wheels until the gold shows up (unless you kill the boss too quickly, losing the gold chest). You get a brown one at the end regardless of whether you get the gold one from the spins or kill the boss too quickly and miss it.
Bosses can drop gold chests. I think all bosses can. However I strongly believe that gold chests from bosses on any stage other than exp sea dragon levels are significantly rarer than gold chests from spins. It certainly happens--just not very often, as far as I can tell from my talks with other players. On average, they should be about a fifth as common as regular gold chests. I and a few friends have experienced drastically lower odds everywhere but on the sea dragon maps. But it could just be luck.
One last note: gold chests get rarer as you move up the chapters. In the early chapters, it's quite possible (even probable) to get all four card types (two from brown chests, two from gold) in your first run of a stage, earning you the bonus. I've found that in chapter six, I can run a stage with the 1.5x drop bonus a dozen times without getting a single golden chest. I'm not saying that's broken--just to be prepared to have to work for your upper-level bonus cards.