Multiplayer Trophies are mostly a negative experience for players. As time progresses many of these Trophies become unobtainable or significantly harder to find players to play with in order to unlock them. Any Trophy no longer obtainable should not count towards overall % completion or the Platinum Trophy on Playstation.
If these must be incorporated into a game, it should be ensured all multiplayer Trophies can be obtained either privately via a peer-to-peer connection or via an alternative method of obtaining in the single player mode of the game. This ensures they can be obtained even when the multiplayer aspect of the game dwindles. They should also be placed in a separate sub-category like how DLC Trophies are handled on Playstation.
Multiplayer Trophies tend to veer towards being heavily grind-centric such as reaching the highest online ranking in competitive or amassing a high amount of total kills. They can also be highly dependent on luck and circumstances relating to the actions of other players. This makes Multiplayer Trophies some of the worst that a game usually has to offer - especially if the Multiplayer mode was tacked onto a Single Player game that didn't need it.
Overwatch - The Floor is Lava
Extremely dependent on luck and skill.
Bioshock 2 - Choose the Impossible
Tacked onto a single player game. Servers empty. Grind-centric.
Batman: Arkham Origins - Predator Paragon
Servers empty. Requires 7 players minimum. Can now only be obtained via deliberate boosting.
Street Fighter V: Champion Edition - Let's Fight Someone Strong!
Insane skill requirement and grind-centric. Need to be a professional player.
Dissidia Final Fantasy NT - Hardened Veteran
Grind-centric.
Armored Core V
Servers shutdown, all 21 multiplayer Trophies unobtainable.
The following Trophies are a mixture of simple, fun and absurd objectives that encourage creativity and exploration. If a game must have Multiplayer Trophies than these are the best kind to incorporate into your game.
Halo 3 - Mongoose Mowdown
Portal 2 - Friends List With Benefits
No Man's Sky - Reunion
Monster Hunter World: Iceborne - Helpful Hunter