Following Destiny's recent patch, which fixed many of the exploits from the Crota's End and tweaked other aspects of the game, a new Iron Banner event is now live.
The mode is a limited time playlist for the competitive multiplayer Crucible mode: its main draw is the removal of an equal playing field, restoring the advantage to the weapons and armor of high-level players. Instead of all gear being evened out to keep matches fair for newer characters, Iron Banner is a no-holds-barred battle where the best items give you a distinct advantage.
That's not to say good play can't be rewarded, but it will be an uphill battle for lower level players. Why play Iron Banner instead of regular Crucible gametypes? Bungie has added limited time drops and purchasable gear that coincide with the event. The vendor Lord Saladin has returned to the Tower (he can be found at the currently-opened back section, up the stairs of the main area) and offers legendary gear you can purchase with enough Iron Banner reputation and marks.
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Playing Crucible Iron Banner matches and completing the bounties offered by Lord Saladin will earn you more Iron Banner Reputation, which unlocks different ranks of rewards at the vendor. To purchase these, you simply spend Glimmer once you have ranked up enough.
The weapons and armor available for purchase include two variations of Iron Regalia Plate/Vestments/Vest (depending on class, Titan/Warlock/Hunter), two variations of Iron Regalia Gauntlets/Gloves/Sleeves (also depending on class), the Rocket Launcher Radegast's Fury, and the Hand Cannon Timur's Lash. Saladin also sells two Emblems, an Iron Banner class item, and two themed shaders. Finally, the Tempering buff is available for one Mote of Light--it will increase the amount of Iron Banner experience you gain for 12 hours.
A level 32 Sniper Rifle and level 32 Auto Rifle can also be dropped for you randomly from matches. Iron Banner will run until January 19, so get out there and win some matches!