It's been a long while since Destiny 2 first came to light, and with it having elements that make it akin to an MMO, it's only natural that it ended up hosting millions of Guardians worldwide. While it may not be the easiest game to get into due to the complexity of its main gameplay systems, it's often quite rewarding to engage with Destiny 2's endgame activities, buildcrafting process, and gunplay. With so many things to do and so many active players, it's no wonder that the community eventually developed its own set of unwritten rules in Destiny 2.
This is often true of most games, especially those franchises that have been around for a long time or those games with a massive playerbase, such as World of Warcraft. While some of the unwritten rules of Destiny 2 might be similar to some of the best live-service games or MMOs, others are deeply unique and rooted in the community by now, including the fact that players typically visit Xur to check out his weekly wares even if they've been around long enough not to need anything from the vendor.
Go to the Tower to Open Engrams and Clear the Postmaster, Even Mid-Activity
Since Destiny 2 offers several rewards that range from randomly dropped Engrams of all rarities to playlist-specific loot, players often feel the need to go check what they got at the end of an activity or encounter as soon as possible. Plus, with the way Destiny 2's Power Level system currently works, players are even incentivized to do so if they're not at the level cap so that they can check whether the new gear they obtained can be infused into their best items. On top of that, the game's Postmaster only has a limited number of slots for retrieved items, so it's often vital to go check as soon as possible, even mid-activity, that nothing valuable is about to be lost to the void.
Let Other Players in the Fireteam Die to Traps or Troll Them in Raids and Dungeons
Destiny 2's Root of Nightmares Raid is just the tip of the iceberg when it comes to endgame PvE activities, and a staple of the community is to host so-called sherpa runs of Raids and Dungeons to teach the mechanics to those who never tried them. One of the perks of the job often involves a good laugh or two whenever said Raids or Dungeons end up featuring traps or otherwise deadly on-activation encounters, such as the infamous Vex portal in the Garden of Salvation Raid. It's not uncommon to do this to unaware players and let them fall or run to their deaths, but it's all in good fun.
Flawless Runs in Trials, Raids, or Dungeons Happen Only When Not Actively Trying
Another common in-joke of Destiny 2's community is that players who are actively seeking to complete flawless runs in Trials of Osiris or some Raid or Dungeon don't succeed because something always happens. It's often customary to just joke about it and say something the likes of "There goes our flawless run" whenever the first teammate dies or is disconnected, causing the attempt to fail on the spot. This is not uncommon even for solo players, who end up getting a flawless completion when they are not actively trying to do that.
Encounters Start With Either no Rally Banner Used or Several Planted At the Same Time
Some Destiny 2 PvE encounters and activities feature Raid Banner spots where one can plant their own consumable item to provide themselves and the rest of the team with an instant refill of Super and ability energy as well as Special and Heavy ammo. However, in part because Raid Banners are consumed on use and one has to go to Destiny 2's Tower to get them, in part because players are waiting on others to use one, some encounters just end up starting with no Raid Banner placed at all. The other option is that multiple Banners are placed at once, instead, ultimately wasting all those used after the first.
Destiny 2 is available on PC, PS4, PS5, Xbox One, and Xbox Series X/S.
