343i's explained Halo 5's REQ Points system - to an extent - through a post on the studio's official site.
The update came after concerns were raised online regards the implementation of the system, which'd see players able to deploy items such as weapons, armour and more they'd 'bought' onto the battlefield. Questions were raised not only it potentially unbalancing multiplayer, but also that players could also buy REQ Points with real-world money.
REQ Points are earned through play, which can be used to buy REQ packs randomised loot drops essentially, that include "unlockable weapons and armors, skins, assassination animations, and more". You'll also get a pack as you level up your Spartan Rank.
"While players will earn REQ Packs across both Arena and Warzone, only cosmetic items can be used in our Arena experience. This is to ensure that all players start with the same weapons and abilities as part of our vision for the balanced, competitive play in Arena multiplayer," 343i stated in its Waypoint post.
In Warzone, the game's 24 player mode however, you can deploy these unlockables. How and when's, according to the studio, is based on "in-match REQ Level and Energy systems, which are driven by player and team performance within the mode". It seems you earn Energy through gameplay, which then can be spent on accessing a weapon - but each costs a different amount of Energy. You want a bigger gun, it's going to cost you.
What gameplay requirements decide collecting Energy is yet to be explained. Kill streaks? Head shots? Teabagging? We'll be updating with more info as we get it on this.
While the team say REQ content's earned through play, they'll "also give players the option to purchase REQ Packs as a matter of convenience, with a portion of the proceeds going toward prize pools for the Halo Championship Series."
/Josh