Strikes are 3 player lengthy co-op missions that you can complete as a team for better rewards one you unlock them in destiny 2.
Each mission will see you advance through various game areas and fighting your way through enemies to reach a boss target that you need to kill. The enemies will have unique strategies and actions to complete to defeat them. Check below for a brief guide to completing each event.
Strikes are unlocked once you complete the story mission 'Fury' and speak to Zavala at the Farm. They will become available as an option in your Director.
There are 6 Strikes currently although one is a PS4 exclusive for the time being.
The Pyramidion
The Inverted Spire
Exodus Crash
The Arms Dealer
Savathun's Song
Lake of Shadows (PS4 exclusive)
Nightfall Strikes are a version of the Strike mode as above but with increased difficulty. One nightfall sill be available each week following the weekly reset which rotates through the roster each week.
To unlock Nightfall Strikes, you first need to have unlocked strikes. Then complete two of them, and reach Power level 230.
Difficulty changes include harder enemies, modifiers that make some Weapons more or less powerful and a timer that limits your time to complete the mission. Although time can be gained back in combat.