I was replaying the Halo Combat Evolved campaign on heroic again and was amazed at not only how well the gameplay held up, but how well the game design has aged and maintained its effectiveness.

It is really startling how well Bungie designed every aspect of the game, from the health system to the enemies to the weapon sandbox. Each aspect reinforces each other in a way that you rarely see in modern games (including Halo games), where numerous gimmicks are stacked on top of each other and game design is used because it is industry standard, not because it is integrated into the core loop of the game.

Halo Combat Evolved: The two-weapon limit

The first part of Halo, and arguably the most important, is the weapon sandbox and how it plays in campaign. There is definitely a bit of older school design here from games like Doom, where control of both which weapons spawn and how much ammo is made available is a core part of how the campaign progresses. This forces the player to adopt different play styles as the game progresses. Each weapon in the sandbox has a particular niche, and does certain things better and worse than others. This plays into something that Halo popularized but no other game has really understood, the two weapon limit.

In most games they add a bunch of different weapons that are basically the same but with the spread and rate of fire tweaked. You still end up with the same ~10 types of guns in most modern FPS’s. Because Halo makes each gun unique, and makes the very powerful ones (sniper, rockets, and shotgun) have more limited ammo they naturally force the player to make decisions with which guns they can carry. If they don’t have the gun on them they cannot pick up the ammunition packages, which means that carrying an empty gun may be worth it, or may be a waste.

The fact that you have to choose between carrying a sniper with 4 rounds or a pistol with 60 is a decision point that makes the player think. In something like CoD you really don’t need to worry about which gun you have since all are effective, and most enemies die quickly.

Halo: Combat Evolved

Halo CE’s enemy design

The second part of Halo’s design that works to integrate this is the enemy design. Halo’s AI and enemy sandbox has been talked up to death, but it is so fundamentally good that it really deserves to be. The split between the first and second halves of the game really illustrates how well Bungie understood its game, since they perfectly introduce each enemy the players must face and how the AI of those enemies work. The first half has the covenant, who are split into 4 unique groups.

The Covenant

The Grunts provide the basic easy to kill enemies, and by making them both easy to kill and capable of surprising the player (specifically with grenades and how quickly 4 plasma pistols can burn through your shield), they allow the designers to fill the sandbox with enemies but not overwhelm the players.

The Jackals force the players to think about positioning. Because their shields are strong enough to waste your ammunition, and they are accurate enough and don’t flee, they are dangerous to leave behind you. So you have to learn how to use grenades, map positioning and accuracy to eliminate them. This is really effective at teaching and making the player engage in the larger and more open level design and parts of the game design besides “shoot till dead”.

The Elites provide the best enemy to make the player react to them, rather than just hunt through the level. Their recharging shields function the same as your own, so there is no need to explain how they work to the player. They are more accurate and deadly than the Grunts and are tough enough to beat the player head to head on heroic and legendary. This creates a decision point in combat, where the player must decide to kill the weak enemies to remove their damage or kill the elite while ignoring their fire and make them flee. It is smooth and intuitive.

The Hunters are a really good boss enemy. They work in pairs, so the player cannot just focus on outmaneuvering one, they must naturally focus on separating both and eliminating them separately in the level layout. If it weren’t for the pistols dealing such high critical damage that they kill the hunters in one shot they would be perfect to pressure the player.

The Flood

The Flood is truly the addition that makes Halo, and why I think the second half of the game is by far the best. They are introduced in a really clever way. Bungie did not want to overwhelm the player right out of the gate so they split the Flood introduction in two. The first time the player meets them, the enemy sandbox has only weak enemies, and the only enemy you really have to fight is the Flood after their introduction.

The second level that is Flood only is regularly hated on, but the Library is really effective, especially when used against players who are running through the game the first time. It combines the ammo restriction (shotgun ammo isn’t common, and if you have to flee before looting the Flood corpses then you can run out of ammo quickly) and the endless waves of Flood to effectively convey the combat loop needed to fight them.

The Flood function unlike any of the Covenant enemies, and for the player to completely change their gameplay. When fighting the Covenant you are the hunter, moving around the map and pulling back when you need to recharge. This works because the Elites function in a similar manner, always waiting to recharge before attacking, and the Grunts and Jackals stay with them or flank. The Flood constantly charging you forces you to change, using the battle map to run and kite them, while being unable to recharge your shields. It is a perfect ludo-narrative connection to what the Flood are, a relentless and unforgiving plague.

Bringing the enemy and the weapon sandboxes together

Where this enemy sandbox really connects with the game is how it connects to the weapon sandbox. Each type of weapon excels against one kind of enemy but fails against another. This is really only noticeable on heroic difficulty and higher because that is when the differences in enemy resistances really stand out.

Halo: Combat Evolved

Take the sniper. Against the Covenant, it is by far the best weapon. You can kill Elites in 1-2 hits, Hunters in 1, and the Grunts and Jackals both die quickly to it. It also allows you to take the Covenant out at range, without exposing yourself. Against the Flood it is useless. It does basically no damage. They are often too close to make use of its accuracy, and the low ammo capacity makes it weak against hordes of enemies.

The shotgun is the opposite. On heroic and greater it is really bad against elites (they can kill you quickly once you get close enough to pop their shields with it), Grunts can take 2-3 blasts before dying, and Jackals are basically immune to it from the front. This means that when you face both enemies you have to use more flexible weapons, such as the plasma pistol or magnum, which don’t, in turn, exceed against any one type.

The Sentinels provide an enemy similar to the Elites, but they add an element of verticality to the engagements, though aren’t used enough to talk about much. This design relies on the two-weapon limit. Without it, the enemy’s weaknesses would matter far less to the player out of combat.

Halo CE’s health pool mechanic

The third part of Halo: Combat Evolved that really works well with the two above systems is the recharging of health. Most FPS’s copied Halo in this regard after its release. All for good reasons, it encourages players to be more aggressive, and it is more forgiving to the player being surprised or the level design being sloppy.

But most FPS’s missed that Halo used this health both in a ludo-narrative way (shields) and to encourage a specific interaction loop with their enemies and levels. Halo’s levels are big and open, meaning that moving around and finding cover from enemies involved more decisions from the player than “hide behind this chest-high wall we put in the small linear path”.

The Elites are the most dangerous enemies, and also recharge shields. The Hunters are also dangerous enough to take your shields off quickly, and their AoE attacks prevent you from taking cover. This means the player needs to explore and know the levels to effectively combat them. The Flood will rush you, meaning the shields are more of a timer for how long you can fight them rather than a forgiving pool of health to take risks. So the player is always making a decision between recharging shields and having a stronger or nearer enemy to fight.

…compared to other games

When you play a game like CoD, you will poke up, kill three enemies, go back down, repeat. Arena style games with quick to kill enemies such as Doom and Quake made the player leave the safety of their positions to find pickups, and consider how to engage while minimizing risk. It is telling that a lot of games (Doom, R6 Siege, Metro, Battlefront, PUBG) have moved back to the health pool based approach, and brought back the old school arena style pickups. Halo realized that by integrating regenerating health they had to fundamentally change how a player interacts with the game and the health system, while most FPS’s just slapped it on top.

Other tidbits of Halo CE’s game design

There are loads of other small touches that make Halo: Combat Evolved fantastic. Every vehicle that players can enter is vulnerable to having the player sniped out (Scorpion Screened Turret, Warthog, Ghost, Shade, and Banshee). This means that even in a vehicle you cannot ignore your health and shields. While running players through the same levels was a budget issue, the addition of the Flood and small changes to the layout (T&R-> Keyes changes the layout, adds a new section, and limits where you can run from the flood, AoCR-> TB removes several sections and replaces them with banshee flight, the Maw is basically a new level) all make them feel new enough and changes how the game is played. Bungie made it so that in certain levels specific weapons are rare or common (see no pistol in T&R, or loads of sniper ammo in TB).

In conclusion

Doom 2016 is the only game in recent memory that I think really integrated its game systems in a cohesive way like Halo: Combat Evolved. Halo CE does have some problems (the copy-paste rooms are annoying, the Library was about 1/3 too long, the plasma pistol, magnum and shotgun being way too good, and not having enough three-way engagements), but the combination of how each game design element makes the players face a decision, and have it all come up naturally by the simple way that each system acts, is genius.

I think even later Bungie Halo games forgot some of these lessons. Halo 2 had too many small rooms to fight waves in during the campaign, and the weapon sandbox began to have redundant weapons (Carbine and BR, Fuel Rod and Rocket, etc.). Certain enemy combinations became broken (shotgun Flood springs to mind), and the enemy sandbox became far less elegant (drones are basically Sentinels for Covenant sections, the Enforcer Sentinels are a boring boss fight, and Brutes are a poor mix of Flood and Elites).