2 unclassified UNSC ships (Threshold System)
Recommended number of players:
There are two parallel human battleships, possibly Cruisers, which have had the exterior bulkhead removed and a good portion of the interior exposed to space. There are four teleporters on both ships, two on the first level and two on the fifth level, which are the only means of transportation between the two ships. This map is usually picked by hosts for its extremely exciting sniper and rocket battles. Other hosts may turn off sniping to force players to board the other ship. This usually results in a frenzy of explosions and gunfire near each teleporter as each team frantically tries to stop the other team on their ship. The ships are in fact not that far apart, in truth it is simple to throw a grenade to the other ship.
There are five symmetrical floors on each side, and are exact mirror copies of each other. Teleporters are found on the 1st and 5th floor, each leading into the exact same place on the other side. On the top right corner of each base (looking out), there is a small indent with a power-up.
Learning the layout of this level is more important than most other maps, as the level can be very confusing to inexperienced players, similar to Chiron TL-34.
- An interesting way to simulate ship-to-ship combat is to have 16 players, eight per team, loaded with all Rocket Launchers.
- It is not at all uncommon in any game type to find yourself standing directly above or below an enemy as the ships have several floors, with each floor number marked on the wall. Often times, one player will come through a teleporter and run right into another player without warning.
- Another popular game type on Boarding Action is all Snipers, in either Team Slayer or CTF, because of how many parts of the map are remote to each other, the fact that you can see half of the map from almost any area, and that close range weapons can't reach to most parts of the map. It is possible, however, to headshot an enemy player using the pistol when the shooter and the target are on opposite sides of the map, but this is rare due to the massive distance.
- There is an ideal sniper location to the left of the sniper rifle, where it is arduous to locate someone unless you already know of the place. After sniping, though, to avoid giving up your hiding place, back into the corridor and out of sight. If you’ve been spotted, then you can simply jump between the pillars to land on an overshield.
 Capture the Flag
- If you wish to be the flag carrier, the most direct method is to go through the teleporter on Level 5 and then proceed down to the enemy base. First, you should spawn within close proximity to the flag. Then, go to the left of the flag and go up the first ladder you reach. You should grab the flag, as it will deter any pursuing enemies and offer a quick getaway. If it is vacant, though, don't panic. There is also the Fuel Rod Gun for similar purposes (in Halo PC only). Note: do not grab the flag if you intend to score; eventually, the enemies will simply overwhelm you, grenade you or fire from a relative distance. Run the moment you come within contact of the flag and then scram. However, don't follow this unless you have set up a plan. Position snipers and escort for the getaway. Usually, the first scoring will be the simplest, as the opponents are usually composed of disorganized hassles, unless you are facing a large group of players. However, when you are past the wall and almost at the wall, don't celebrate yet, as you are in an exposed area and are prone to enemy sniper fire.
- If you have the sniper rifle, a good idea is to try and take out opponents on the enemy ship while the flag carrier of your team tries to capture the flag or escape back to your base.
- You can use close-quarters weapons, such as the Shotgun, or Flamethrower (in Halo PC) to defend you base, or your flag from being captured by the enemy team.
- Boarding Action is one of the best, if not the best, overall classic team-slayer maps in Halo Combat Evolved. This is primarily because of the fact that it allows almost every player a view of the majority of the map at any given time. It emphasizes long-range weapons; such as the sniper rifle, pistol, fuel rod, and rocket launcher. However, it provides many oppurtunities for close quarters combat with weapons such as the shotgun or assault rifle. The map is fairly easily navigated to an experienced player, allowing power-ups and power weapons to be controlled quickly. The teleportes allow for almost complete map control to the team who has secured the upper decks, but can also prove to be a weapon for the opposition, as they can be used to insert forces directly behind enemy lines.
- One of the best strategies for team-slayer, and one that has been utilized succesfully in many high-level games, is to control the entire upper floor. Once done, one person should be able to control the entire map by teleporting back and forth to his/her sniper and fuel rod spawn points. Since there are two of each, a second person can do the same for the other half of the map. In skilled hands, the sniper can kill in 1-3 shots. It is especially powerful if the target is going up ladders, since this makes it almost impossible for them to evade. The only way to counter this is to climb up backwards, and fire at the sniper as you go. And, if ever an enemy should take cover behind a wall, utilizing the fueld rod's blast radius should kill them if their shields are already down. Remember, the fueld rod has a much greater range and blast radius in Combat Evolved than in later installments to the Halo series. Make sure to collect ammo as needed. If necessary, it is possible to retreat by jumping directly into the overshield or cloaking spawn (respective to which side of the map you're on), and from their to collect whatever weapons you need to reclaim the sniper's nest. Rocket launchers, owever, should be avoided in most circumstances, as their projectiles are easily spotted, and generally take too long to arrive at their destination.
- In conclusion, Boarding action is an incredibly fast paced and dynamic map, which allows for all styles of infantry based play. Though CTF might be a little broken, as the majority of the spawn points are out in the open and easily targeted by snipers.
- This map is one of the few multiplayer maps which includes all the weapons and power ups.
- If the levels model is extracted it can be noted that both sides of the maps are actually of the exact same model ship but on opposite faces of the ships (from above, one side red and one side blue). In addition, the model used in the level was actually copied right next to the original facing the opposite way. This can only be seen if the levels model is extracted from the file.
- By spawning a Banshee the player can explore the top of the ships. They are completely flat and the opposite sides do not have anything on them.
 Easter Egg
When examining levels\test\boardingaction\bitmaps\deckdecals.bitmap, one will find a photograph of an unknown woman hidden inside the mesh.