The most useful site I have found concerning Daily/Weekly challenges in Reach is British blogger Matthew Vose's "Halo Reach Daily Challenges", hosted by WordPress:
http://reachdailychallenges.wordpress.com/category/daily-challenges/He lists all of the challenges (like Bungie does) but also provides (along with his followers) informative commentary on how to achieve them. (Unlike Bungie.) For example, check out the recent weeklies:
http://reachdailychallenges.wordpress.com/category/weekly-challenges/Now to the topic at hand...
Yesterday's challenge, "Golden Opportunity", had me taking a break from building our new content system to actually play the game for a bit. As you probably know, the description for this challenge reads:
Find and kill the Gold Ranger-class Elite in any Campaign mission on Heroic or harder
After some Google searching, I learned that this challenge had previously appeared on Jan 30. Matthew documented it back then on his blog here:
http://reachdailychallenges.wordpress.com/2011/01/30/30th-january-reach-daily-challenges-commentary/As far as I know, it has only appeared these two times. Please update us on other dates if you find them.
The good news regarding this challenge is that it prompted me to get some great in-game footage of all three of the BOB spawns on Winter Contingency. I also now understand what makes them spawn, and what makes them begin their game-engine script to eventually disappear. More on that later.
The bad news is that I feel we missed a "Golden Opportunity": this challenge provides an unprecedented method to ACTUALLY CONFIRMING what Bungie considers to be a BOB, and what is not: if you don't get the challenge when you kill it, it's not a BOB, right?
So why in Gherjsz's Green Earth did I not think to go after the Boosting Banshees instead?
Dear SGP members: please provide all you can (films on your file share would be perfect) on how you got this achievement yesterday, if you got it.
I got the challenge twice (multiple gamer tags) on Winter Contingency using two of the three BOBs on Winter Contingency... so I can vouch for those.