For starters, the REQ and loadout system ought to be simplified and streamlined. The system as it is now is too bloated, slow, and prone to lagging for several minutes. Instead of having players pick one option at a time every match, just let them make custom loadouts for Warzone. For instance, let’s say your preferred weapons a Sentinel Battle Rifle with Laser Sights, paired with an SMG equipped with Recon Sights and Stabilizers. And your preferred equipment is Speed Booster. Instead of going through the dozens of variants of each weapon and armor mod one at a time, every time, you could just assign these to a loadout and pick all your favorites in an instant. With this, players would spend less time in the menus and more time playing the game.
As for REQs, calling in power weapons and vehicles, there are a number of improvements that could be made. First, get rid of any non-unique variants. No more Warthogs that come in a million different paintjobs, no more weapons that are just marginally better versions of the originals. Second, get rid of the RNG factor in obtaining REQ cards. How many people have gotten awesome cards, like Prophet’s Bane, only to never use them for fear of wasting it? Instead of saving up points to spend on random packs, let us buy REQ cards directly. Then you could stock up on all your favorite weapons. You could get as many sniper rifles as you want, or spend it all on Wasps. The energy system would still be in place to prevent players from having power weapons on every spawn. Which brings me to my third point.
Make REQ tiers unlock based on time, not score. The score-based unlocks make it far too easy for players, especially coordinated teams, to steamroll other players and trap them in their base with tanks, rockets, snipers, and air support, while the other team can’t get anything better than an assault rifle. While we’re at it, lets improve the home bases to have multiple exits so there’s less risk of kill farming becoming an issue again, and the defending team has a chance to take a base back without fruitlessly throwing themselves at a wall of bullets. Emergency teleporters would work really nicely here.
The PVE aspect of Warzone needs some attention as well. I know that everyone loves to hate Spartan IVs and call them a bunch of wimps, but this shouldn’t actually be a cannon thing. Whenever I play Warzone, I shouldn’t feel completely helpless against a single Elite without 3+ other players backing me up. The baseline difficulty for PVE encounters should be Heroic, not Legendary. And they shouldn’t be able to throw grenades/shoot at me when they’re not even looking at me. Enemy encounters, especially bosses, should be randomized and much less predictable than in Halo 5. And I think the score value of legendary bosses should be toned down, with new, non-boss based objectives created for more opportunities to score points. Such as retrieving supplies, rescuing marines, or sabotaging enemy equipment. Lastly, when we take bases away from Covenant/Prometheans, they’re basically never seen again. They should try to retake bases from the players every now and then, and regain control of them if they’re not repelled, causing players to lose the option to spawn there until it is reclaimed.