Loadouts work pretty well too. As expected, they're weapon sets that you can choose to start each respawn with - although, this being Halo, you can still expect to find other weapons scattered around the map. Composed of a primary and secondary weapon, they also have a third slot for armour abilities.
These seem to be a refinement of Halo 3's equipment system: they're a reusable skill, mapped to the left bumper, with a bit of a cooldown to manage. Jetpacks are an armour ability, for example, and other ones that might pop up include a sprint, a kind of shield overcharge that comes with a ground-punching animation that either looks cool or faintly silly depending on what side of 16 you find yourself on, and active camo.
In game types in which you find yourself playing as Elites, you may see an additional option to perform a quick barrel roll, covering a lot of extra ground very swiftly, but be warned - it comes with the distinct possibility that you'll cartwheel yourself over a cliff.
Loadouts are customisable much of the time, but specific modes will limit your choices in entertaining fashion. Bungie has recently announced four new game types you can look forward to in the beta: the most complex of them is Invasion, and loadouts are central to its appeal.
Invasion is something of an experiment for Halo: a large-scale Battlefield-type mode that can only play out on specific maps, which divides players into two teams of four - the defenders playing as Spartans, while the attackers are dropped into the big metal shoes of the Elites.
It's a round-based game that has multiple stages, each with their own objectives. For the first stage, Elites have to overrun the Spartans' higher ground and capture a series of areas. This opens up a larger portion of the map, unlocking vehicles in the process and providing Elites a handful of new capture points to tackle. If the Spartans fail to defend those, Elites can then collect a data core from the Spartan base, and try and get it to an extraction point to win the round.
Beta players will be doing all this on Boneyard, a truly colossal map built from two large arenas broken up with warrenous military installations. It's brilliant fun, particularly if you're attacking, but even if you get stuck on the Spartan side, there's a real thrill to be had as you stand at your starting position and watch Elites rushing towards you from below.
Each stage of the game has its own pace, from the frantic firefights that break out around the first capture points to the more drawn-out vehicle battles that erupt around the second, and the final race to get the core to the waiting Phantom steals all the best bits of American Football in a mad touchdown dash across dangerously open ground.
It's a lovely piece of design. Attackers are suddenly forced to defend a single, fiercely vulnerable player, and the whole thing is given an extra kick by the fact that, at each stage of the game, the loadout options open up significantly. If Spartans play badly enough and lose the first capture points, for example, their choice of just two equipment sets will be doubled. There's a bittersweet feeling as you find yourself reaching the good stuff because it invariably means your team is taking a kicking.