Halo 3 Community has announced a montage competition for 2019. The rules are as followed:

All montages must be made after 1/7/19 All montages must have the “#H3CMC” intro All Montages must be minimum of 2 minutes Can submit a “Funtage” Can submit Halo 1, Halo 2, & Halo 5 montages (Just a warning all judges are H3 players) Only 2 submissions per player To submit your montage click here Prize pool is $600 (1st = $500 USD, 2nd = $100 USD, and 3rd = 12 Month of Xbox Live Gold) Deadline is 8/1/19

For more information head to their website. Good luck!