The ULTIMATE Doom Ultra-Nightmare Guide

"In the first age, in the first battle, when the shadows first lengthened, one stood. Burned by the embers of Armageddon, his soul blistered by the fires of Hell and tainted beyond ascension, he chose the path of perpetual torment."

Ultra-Nightmare is a challenge and committing to it can feel like perpetual torment. However, through a combination of trial and error, solid strategy, and in-depth level and game knowledge, you can beat Ultra-Nightmare.

• Run the game at a graphical setting that allows 60 frames per second easily.
  
• Set your field of view (FOV) to around 114 (my preference) to allow for better reaction and evasion in battle.
  
• Bind weapons to keys and mouse buttons that you can easily reach and switch between.

Health, Health, Health, Health, Ammo, Ammo, Ammo, Ammo, Armor, Armor, Armor, Armor is a particularly good upgrade order. Make sure you know where every Argent Cell is.

Argent Cell order is crucial. There are around 3*10*2 = 60 different ways you could approach filling out the 12 slots. Health should be heavily weighted in your selections at the beginning because HP is abundant and easily refillable. Armor is rare and capped very low. Megahealths, which can be acquired in level 05 and on, mitigate the need for armor upgrades and even exceed its max cap of 150 (a Megahealth is +200HP, +200 armor). Armor upgrades should be your last four picks. Your health/ammo order in the beginning is up to you, but I swear by Health, Health, Health, Health, Ammo, Ammo, Ammo, Ammo, Armor, Armor, Armor, Armor.

Rushing Environmental Resistance completion first is widely agreed upon to be the best initial strategy. Make sure you know where every Elite Guard is.

Best to start off with because it eliminates damage from explosions that are out of your control and also limits self-damage.

1. Hazard Protection (1 token): Damage taken from explosive barrels and environmental sources is reduced.
   
2. Self-Preservation (2 tokens): Self-inflicted damage from weapons is reduced.
   
3. Barrels O' Fun (3 tokens): Immunity to damage from explosive barrels.

Worthless for our purposes.

Largely improves the equipment items, specifically the Hologram, which makes the game much easier.

1. Quick Charge (2 tokens): Equipment recharge duration is reduced.
   
2. Stock Up (3 tokens): The total number of equipment charges is increased.
   
3. Rapid Charge (4 tokens): Recharge duration is further reduced.

Prolongs and enhances powerups, also turns them into HP refills adding more safety nets to the mode.

1. Power Surge (1 token): A blast wave is unleashed when a power-up expires.
   
2. Healing Power (2 tokens): Health is restored to maximum when a power-up is activated.
   
3. Power Extender (3 tokens): Power-up durations are increased.

Speeds up your offensive attack and enhances the quick switching style. Its third level upgrade hastens weapon mod switching, which is useless.

1. Adept (2 tokens): Weapon changing time is reduced.
   
2. Quick Hands (3 tokens): Ledge grabbing speed is increased.

Hazard Protection, Self-Preservation, Barrels O' Fun, Quick Charge, Power Surge, Healing Power, Power Extender, Stock Up, Adept, Rapid Charge, Quick Hands

Completing 1, 4, or 7 rune trials gives you 1, 2, or 3 active rune slots respectively. Make sure you know where all the rune trials are, especially the ones you want to use.

There are many useful runes in the game. Some runes will be good for you but not for others. I stray away from glory kill runes, for example, because I think glory killing is not safe in the mid to late game, so I wouldn't want to incentivize it. Below are the runes that I believe are the most effective. Helps early game when ammo is scarce. Mastery drops BFG ammo from demons. Best rune for boss fights. Can suck in 200HP from across the arena in an instant. Makes the Hologram even more powerful. Allows the Siphon Grenade to give armor, creating obvious synergy with Rich Get Richer. Gives infinite ammo at high armor levels. Infinite Ammo makes boss battles much easier, and allows you to use Siege Mode to your heart's content. Also incentivizes you to not get hit. Gives you a second or even third chance at life when mastered. Eliminates nerves and possible tragedy, can save your run. Resets every level.

Some mod choices are up to debate, but some are no-brainers. Some masteries are worth it, some aren't.

The infite-ammo UAC pistol is useful in 01 and 02 for headshotting possessed, exploding cans, doing damage to far-away Imps and Soldiers with alternate fire, and for preserving ammo. However, after that initial utility, the pistol drops off to near complete uselessness. The pistol is not nearly powerful enough even under mods nor is the arsenal's ammo scarce enough for it to be even close to worthwhile from 03 and on. Do not bother modding it. Acquire: 01 The UAC
Ammo Pool: Shotgun Shells
Modding Reccommendation: Explosive Shot and mastery

The Combat Shotgun with Explosive Shot is a versatile weapon, good until the very end of the game. It one-shots low-level demons on level 01, which is extremely valuable. It can be used to great effect in cleaning up glory killable demons from close, mid, and even long range. The mastery, Cluster Strike, is great on direct hits on mid-level demons such as the Hell Knight or Revenant. The alternative Charged Burst mod is perhaps the worst mod in the entire game and makes Ultra-Nightmare significantly more difficult. It is also immediately overshadowed in its application by the Super Shotgun.

Acquire: 04 Argent Facility (early), 05 Argent Tower
Ammo Pool: Shotgun Shells
Modding Reccommendation: Do not upgrade

The Super Shotgun is excellent at killing lower-level demons in just one shot, such as Possessed, Imps, Soldiers, and Hell Razers. Its other valuable use is cleaning up staggered or "glory killable" demons from close to mid range. If any demon is staggered, you can finish the job with a single shot and move on to your next threat. It is also great for killing Pinkies in the back. The Super Shotgun's upgrades are a waste of weapon points. It's great on its own. The level 1 upgrade makes reloading faster, which is useless, since we don't reload. You'll have to spend 9 weapon points just to get piercing rounds, which results in rare double kills. The mastery takes 30 double kills and is not worth it in the slightest.

Acquire: 02 ResOps (early), 03 Foundry
Ammo Pool: Plasma
Modding Reccommendation: Either and mastery

The Plasma rifle unmodded is one of the worst weapons in the game. Because the rounds are so slow, it is only effective against pursuit-type AI, such as the Hell Knight. A downside to the Plasma Rifle is that is draws from the same ammo pool as the best weapon in the game, the Gauss Cannon, so when both are acquired, the Plasma Rifle is only used for one of its two mods in mod-specific occasions only. The two mods are both good. Stun Bomb allows you to freeze Pinkies and shoot them in the back. This creates great peace of mind, mitigating a big threat in the game substantially. Heat Blast has a large advantage early on in that Expanded Threshold can be bought with one weapon point, allowing for big damage by 02. It's like a mini BFG that can get you out of a bad situation where you're overwhelmed. It's amazing under 4x, too.

Acquire: 05 Argent Tower (early), 06 Kadingir Sanctum
Ammo Pool: Plasma
Modding Reccommendation: Siege Mode and mastery

The Gauss Cannon with Siege Mode is the best weapon in the game, and it isn't close. Gauss Cannon with Siege Mode one-shots and mutli-kills 82% of demons and 100% under 4x. Unmodded, the Gauss Cannon one-shots Security through the shield.

Acquire: 02 ResOps
Ammo Pool: MG
Modding Reccommendation: Micro Missiles and mastery

The HAR is bad on its own. It is weak at mid range and not useful beyond 03 or so. The Micro Missiles mod's homing quality and splash damage makes for an effective long-range weapon with excellent hit stun on all demons, and is perhaps one of the best and most satisfying weapons to use under Haste and 4x. Micro Missiles is also the easiest mod to master in the game. You can master it by killing four demons with the missiles in five seconds, which gives you fully automatic Micro Missiles. Pair that with Rich Get Richer and you have an infinite missile stream. Mastered Micro Missiles also do great splash damage to distant charging Pinkies. Tactical Scope is just not that useful. Limiting your FOV by using the scope can also lead to a lack of awareness, resulting in combat and platforming deaths.

Acquire: 06 Kadingir Sanctum (early), 07 Argent Facility Destroyed
Ammo Pool: MG
Modding Reccommendation: Mobile Turret and mastery

The Chaingun with Mobile Turret is massively underrated. It is excellent at quickly killing Cacodemons as well as saving ammo for the Gauss Cannon and Rocket Launcher. It is incredible under Haste or 4x, quickly killing anything it's pointed at. When mastered with Rich Get Richer, unending fire is possible. Mobile Turret is particularly effective against mid-level demons, Pinkies' backsides, and in boss battles. Gatling Rotator doesn't suit the high octante quick switching playstyle at all, so it's not particularly useful.

Acquire: 03 Foundry (early), 04 Argent Facility
Ammo Pool: Rockets
Modding Reccommendation: Remote Detonation and mastery

The Rocket Launcher with Remote Detonation is probably the second-best weapon in the game. The Rocket Launcher should be saved for and immediately maxed on 03 in my opinion. It makes the early game much easier. This mod allows you to deal damage en masse, out of the line of sight. The mastery causes damage to continue after the detonation, resulting in even more damage after evasion. The Gauss Cannon quick switch to Remote Detonation and back again technique is a devastatingly quick way to deal with heavies and bosses. Remote Detonation is more versatile than Lock-On Burst in my opinion. Others will disagree. The big caveat to Remote Detonation is it takes discipline. You can end your run easily with a bad detonation self-damage. If you don't trust yourself, pick Lock-On Burst.

Alternative weapons are largely underused by non-Ultra-Nightmare players.

Acquire: 02 ResOps
The Chainsaw is sort of the BFG of the early game. The Chainsaw is excellent at gaining ammo and dispatching Hell Knights in 03-04, making the game significantly easier. Using the Chainsaw constantly early on also makes the Health-first Argent Cell strategy possible. Stun Bomb + Chainsaw can take down a Baron with zero threat later in the game. Acquire: 08 Advanced Research Facility
Use the BFG to its full capacity. Know all the BFG ammo locations. The BFG is a part of why 07-13 is easier than 01-06. The BFG has been cast as an "oh sh--" weapon that you only use in a bind. It is good in a bind, but you should actually use the BFG all the time, even when you're not in trouble. Acquire: 01 The UAC
The Grenade is useful from 01-05 before you get the Hologram. Early on in 01-03 it is comes in handy for evasion or for when you're overwhelmed with a weak arsenal. However, unlike Doom Eternal, you have to stop firing to throw the Grenade, making it a questionable choice mid to late game. Acquire: 05 Argent Tower
Irreplaceable. It makes every battle easier because it constantly takes at least a few demons off your trail. Combining it with teleports, lunch pads, and vaulting is an even greater advantage. It shoots at demons, doing no damage, but in turn reveals demon locations. With the Equipment Power rune and the Equipment System Praetor upgrades, it's game-breakingly good and renders the Grenade obsolete. Drop Holograms in an elevated, central location if possible, or at least a location with high visibility. Acquire: 09 Lazarus Labs
The Siphon Grenade is good for bosses in my opinion, since Grenades and Holograms don't really affect bosses much. If you're busting it out in the thick of battle to get health or even armor back it can actually be more trouble than it's worth. It has outstanding synergy with Rich Get Richer, but you have to be smart about it.

The ability to quick switch between weapons without thinking is a huge advantage in Ultra-Nightmare.

Quick switching is when you fire one weapon and then immediately switch to another weapon, and so on, killing animation or rate of fire lag. This technique creates tons of incredible combos, particularly between the Rocket Launcher, Gauss Cannon, and Super Shotgun. However, it demands that you have a key for every weapon in the game. I bind keys around my left hand and on my mouse. I do not recommend using the weapon wheel.

Some demons are much more dangerous than others. You need to develop a natural hierarchy of threats so you deal with the most severe threats first.

1. Urgent Threats: Lost Soul, Cacodemon, Baron of Hell, Summoner
   
2. High Threats: Cyber Mancubus, Spectre, Pinky
   
3. Threats: Hell Knight, Revenant, Mancubus, Possessed Security
   
4. Fodder+: Hell Razer, Possessed Soldier, Imp, Possessed Engineer
   
5. Fodder: Possessed, Unwilling​

Recall that the Gauss Cannon with Siege Mode is so useful that it can one-shot and multi-kill 82% of demon types (100% under Quad Damage):

• The unmodded Gauss Cannon one-shots: Possessed, Unwilling, Hell Razer, Possessed Soldier, Imp, Possessed Engineer, Possessed Security, and Lost Soul (Technically).
  
• Gauss Cannon Siege Mode one-shots (and multi-kills): Cacodemon, Summoner, Revenant, and Hell Knight.​ You can include the Pinky/Spectre if shot in the back.

Playing without glitches, speedrunning, or exploits, your campaign will be between 3.5 hours and 5 hours. That's one reason why the mode is hard—it's tough not to die or mess up over hours and hours of gameplay.

It's helpful to think of the game in three parts. 01-06 is the first part. It is proportionally longer than the other parts, and is by far the most difficult section of the game. This is the part of the game where you will be dying and learning from your mistakes. 06 Kadingir Sanctum is perhaps the hardest level in the game, so I consider it the first big hurdle.

After 06, you begin the middle part, 07-09. 07 Argent Facility Destroyed and 08 Advanced Research Complex (where you acquire the BFG) are among the easiest levels in the game, and are a nice break from difficulty between the two hardest levels in the game, the first being 06 and the second being 09 Lazarus Labs. 09 is the longest level in the game, and culminates with the Cyberdemon boss battle. The Cyberdemon's demise marks another hurdle, the end of the middle part.

After defeating the Cyberdemon, you begin the home stretch of the final four levels, which are more nervous than difficult, because of the high stakes. In these last four levels, you can use Saving Throw, giving you two or three lives per level. You also have max Praetor Suit upgrades, near max Argent Cell Upgrades giving you max Health, max Armor, and max ammo, 3 active rune slots, and the entire modified arsenal at your disposal. This part features the last two boss fights, the Hell Guards at the end of 11 Necropolis and the Spider Mastermind at the end of 13 Argent D'Nur.

You can just run to the end of the level and ignore almost all demons after the first canyon arena. I've done this level in 3:30. This level will quickly become a mere formality.

Elite Guards: 1
Worthwhile Secrets: get the 2 collectibles for the weapon point.

After you get the grenade and drop down, go into the cave on the right. At the end is an Elite Guard. After you get the Praetor Token, drop down and jump the gap to the right towards the Upgrade Module. This skips a whole Imp fight that's messy and a waste of time. The Upgrade Module flies away into the cave when you jump the gap. I emphatically encourage you to choose Explosive Shot. You can run through the battle after the Upgrade Module by killing the Soldier at the far end and running for the cliff. You can ignore the Imp cliff battle by exploding the Imp on the ridge, going through the cave on the left, getting the collectible, and jumping the gap to the flat area. You can ignore a lot of the battle before the final doors by exploding the cliff can next to the soldier, killing the Imp that spawns in the middle, vaulting up onto the ridge, exploding the cans below, and vaulting up to the doors. By the final door there's Health and Armor nearby, and more supplies down the train tracks opposite the doors.

This is one of the most frustrating levels of the run because you're going to be playing it many times. It isn't easy, and it has a long exposition at the end courtesy of Samuel Hayden. Start off by upgrading Explosive Shot with Speedy Recovery, and upgrading Environmental Resistance with Hazard Protection if you haven't already.

Argent Cells: 1
Elite Guards: 3
Weapons: Chainsaw, Heavy Machine Gun, Plasma Rifle (early)
Worthwhile Combat Challenges: kill 2 Possessed with one Combat Shotgun shot, perform 5 different glory kills on Possessed, find three secrets (you should get this naturally just by getting all the Praetor tokens and the Plasma Rifle)

Shoot the cans and use the grenade box at the entrance. The AI can only cross at two points, so you can gatekeep the gaps. Hit the button by the door to vault upstairs to get extra ammo and armor. Once inside the locker room, pick up the chainsaw and refill your health with the HP module. The Gore Nest battle outside the elevator is actually one of the most difficult and overwhelming battles in the entire game, so try to go into it with 20 shotgun shells, 100HP, and a little armor. The key here is to constantly move, vault, and check your peripherals. Stay up on the catwalk and drop down for health and ammo when needed. Beware of hanging Imps; refrain from engaging them. Try to explode them instead. Grenades are probably at their peak most valuable during this battle. There are several cans to launch Explosive Shot towards at the right time. Ignore the Upgrade Module at the top of the elevator for now, since we don't double mod. In the room where you get the Heavy Assault Rifle, push the control panel on the wall. Go to the yellow keycard room and touch the control panel there. Open the floor hatch in the hall on the right and get the Elite Guard in the corridor and the Plasma Rifle in the elevator shaft. Take the elevator back up to the third floor and modify either your Plasma Rifle or your Heavy Assault Rifle. After the Upgrade Module, there's a new yellow keycard door you can go through on the right. Go through the vent and drop down to get the second Elite Guard. All these secrets will also give you a weapon point. Outside the airlock, it's best to just run through, hop up the side vents, and drop down the hatch, ignoring the mayhem outside. It's too hard, so just run past it. After you've gone across the bridge, through the airlock, and pressed the control panel on the desk, there's a long corridor with some Possessed, Soldiers, and Security. Once you kill the Security on the left, go through the door on the left, vault up through the next door and you'll find an Imp, an ammo box, and an Elite Guard.

"You may not agree with our research, but know this: we exploited Hell and its resources because it was in mankind's best interest to do so. What you now see in this facility is the cost of progress. Hmph. But none of that matters now."

This is the level most runners hit a wall and quit. There's a sharp increase in difficulty and complexity, and the environment is one of the more treacherous in the game (The base floor of the level is an inescapable lava pit). A big change is the introduction of the Hell Knight, which I outline how to deal with. Make sure to save your weapon points to max out the Rocket Launcher.

Argent Cells: 1
Elite Guards: 3
Weapons: Rocket Launcher (early), Plasma Rifle
Worthwhile Combat Challenges: kill 3 possessed with one barrel (This can be done at the very beginning next to the Turbine door), Death From Above 3 Possessed Soldiers, find 2 collectibles (They're not out of the way)

A lot of deaths occur here. Use Explosive Shot to kill the guard rail Imp, point-blank blast the other, grenade the Security and follow up with an Explosive Shot. Then keep moving. Grab the yellow keycard, get the collectible, and head back where you came. There's a trigger that brings a Hell Knight, two Imps, and a distant Possessed Soldier and Security. Chainsaw the Hell Knight immediately. Head down the stairs after the skirmish is over. In the lower facility, there's a room you drop into with lots of Possessed. Before you drop down, jump across the room to get the secret Rocket Launcher. Pick up the Gas Canister to refill for future Hell Knights. Be careful not to fall off into the lava. Move away from the Gore Nest back to the large platform so you don't strafe off. Combine Explosive Shots with Combat Shotgun blasts and the Rocket Launcher splash damage to defeat the demons. Heat Blast is particularly useful here. When you cross the main bridge, shoot the cans to kill some of the demons that spawn. Get the Argent Cell on the left. When you move toward the yellow keycard door, a Hell Knight will jump up. Shoot the cans as he approaches. On the assembly line, chainsaw the Hell Knight that bursts through the wall. Grab the collectible.
Get the Chainsaw refill by the vent. There's an Elite Guard in the vent on the far end of the assembly line. Pull the Gore Nest and make your way upstairs. Chainsaw the Hell Knight on spawn. Grab the blue keycard. Jump the platforms down into the blue keycard room. Get the gas canister on the bottom floor. Check for a surprise Hell Knight outside. Pull the Gore Nest, move upstairs. Try to do a little damage out of sight by shooting rockets at the far ceiling or throwing a grenade. Upstairs is a little chaotic. Chainsaw the Hell Knight on spawn. Refill on the HP Module. Again check for a surprise Hell Knight. Before the foundry Gore Nest, upgrade your Rocket Launcher. Immediately max out the Rocket Launcher with your weapon points. This makes the turbine room finale much easier. Before you get the severed arm in the broken bridge room, get the Elite Guard on the bottom far end of it. There's an armor in the vent on the right side of the room. By now you should have Barrels of Fun in Environmental Resistance, giving you barrel immunity. Shoot up the barrels. You want to go into the turbine room with as much HP, Armor, and rockets as possible. There are two waves in the turbine room. Save your rockets. Stick to the bottom level below the turbines for most of the battles. The AI and Imps in particular don't have line of sight on you and struggle to move down there. Getting sniped by Imps is the tough part of the battle if you remain up top. When the first Hell Knight approaches, you can move up the far end stairs to make him platform instead of attack. Pop back down for the second wave, and continue to predominantly stay below the turbines. When the two Hell Knights come from either side, evade and use your maxed modded Rocket Launcher on them. You can again use the far end stairs to make them platform instead of attack. There's an Elite Guard in the hall on the left past the turbine doors.

"You could not have saved them, anyway."

Another precarious level.

Argent Cells: 1
Elite Guards: 4
Weapons: Rocket Launcher, Super Shotgun (early)
Worthwhile Combat Challenges: touch the Rune Stone, touch the Automap

You can easily die if you hastily jump onto the platform outside, due to the slope. If you're moving too fast after you land you'll bounce off the ground, enough for your jump command not to register. Coming outside to the first batch of demons is one of the most chaotic and dangerous moments of the game. It helps to eliminate the Possessed and Possessed Soldier (Who turns into Security if you're not quick enough) first. There's also an Imp close to the right that is ready to fire. Then explode the cans and move to the pillar. To the right of the pillar, there is a small gap to another platform. Getting on this platform puts railings and gaps between you and the demons, making the fight a little easier. After it calms down a bit, a Hell Knight breaks the far fence. You should have the gas to just chainsaw it. Or Stun Bomb + Chainsaw if you have it. Ignore the Imps from far away. Trying to fight them is super tough, because their fireballs are so fast and accurate. Instead, follow the Upgrade Module to the ammo box. Drop down to the metal terrace below. At the end is Elite Guard #1. Turn around and go into the cargo bay area in the cliff face. You'll probably be upgrading either your Plasma Rifle or your Heavy Assault Rifle. Before the gore nest, I think it's smarter to clear the room on the far right first. After this small Imp battle, you can upgrade your health via Argent Cell, or fill it up with an HP Module on the wall. Grab the armor out in the open. Pull the gore nest. It's worth it to use rockets on the Hell Knights. Explode the cans and keep moving in a large circle around the bottom floor. When the battle is over, grab Elite Guard #2 in the raised cave. Remember to "carefully remove the hinges." This gore nest is pretty cramped. Explode the cans on the Hell Knights and encircle the battle area. Don't get caught on the pillars. You can even retreat back inside the facility if you like. Although you technically don't have to enter the Hydroponics Facility at all, I use it for weapon masteries since it's so cramped. It has an Upgrade Module up the stairs that we don't need. I find the exit on the other side of the facility to be useful. It leads to an ammo box. Past the entrance to the cooling facility is a cliff side. At the end is a dead guard with the Super Shotgun in hand. Try to start using it at super close range on lower-end demons, and also for cleaning up staggered demons. After you gain access to the control room and carefully remove the hinges of the argent filter, a Summoner will greet you at the center platform. Stun Bomb + Chainsaw it or get rid of it in the fastest possible way that you can. Summoners are dangerous and make battles more difficult. I've found this arena is easier if you stay up on the top levels and use the launch pads. I haven't found the Haste powerup to be particularly useful at this point in the game, but take it anyway. Just be careful not to fall into the coolant. Leave the cooling facility on the launch pad side, upstairs. On the metal catwalk outside you'll come across Elite Guard #3 on the far wall. Then proceed to destroy the upstairs argent filter, which unlocks the door to the final gore nest area. Take the Berserk and pull the gore nest. Smash everything to bits, especially the Summoner. The level concludes after you destroy the 4th filter.

"Carefully remove the hinges..."

This level is a platforming level first and foremost. Know the platforming patterns by memory. Never jump late on a cycle. Never take a single risk.

Argent Cells: 2
Elite Guards: 3
Megahealths: 1
Rune Trials: Ammo Boost, Equipment Power
Weapons: Super Shotgun, Hologram, Gauss Cannon (early)
Worthwhile Combat Challenges: kill 15 demons under Quad Damage.

Be careful of the Engineers in the battle, they can sneak up on you for big damage. Avoid going into a nook because the Soldiers are really good at putting charge shots into areas. There's an Argent Cell above the Jump Boots room accessed on the bridge side. The tower on the bridge is a detour that throws more demons at you and yields one weapon point from an Upgrade Module that you don't need. You can just ignore the whole tower and jump the bridge gap. There's an Elite Guard down below on the far right end of the bridge before you make contact with Olivia. This battle is treacherous because it's basically a corridor. Blow some cans up to make room for your effort to get the Quad Damage. Focus on the Summoners. When you come across a circular arena such as this one, you can dominate by simply encircling the area and vaulting. Make your way to the launch pad that launches you into a Quad Damage. There are plenty of surfaces to vault to as you encircle the arena. As before, this arena is a big circle, so encircle it and vault around. Use the launch pads excessively, they launch you into ammo and armor. There are high-up struts you can walk along, and a platform with an Invulnerability powerup. Take it when the action picks up. In the control room, there's an Argent Cell in the far end nook, as well as an HP module on the wall. In the hall in front of the ammo box, there's two holes in the floor. Floating in the right hole is a Megahealth. Up past the ammo box on the next floor, the Elite Guard is resting on the middle pillar. Stick to the outer rim and use your Holograms. Use the encircling technique and get the Quad Damage if there's an opening. This is a run out the clock situation. When the countdown starts ticking, make sure you get the Invulnerability powerup so you go into Kadingir Sanctum with nearly 200HP and 200 armor.

Kadingir is the hardest level in the game. Consider it a benchmark. If you can beat this level, you can beat Ultra-Nightmare. This level is long and dangerous with plenty of traps, precarious battles, and deadly platforming. It should take you 25-30 minutes even if you know it well.

Argent Cells: 1
Elite Guards: 4
Megahealths: 1
Rune Trials: Seek and Destroy, Savagery
Weapons: Gauss Cannon, Chaingun (early)
Worthwhile Combat Challenges: get 4 Praetor tokens, kill 10 demons under powerups.

Try to kill the Mancubi before you drop down. Platform around on the floating platforms and roofs. There's one floating platform that leads to the Rune Stone later that the AI cannot reach. Try not to camp on the far end ramp. Encircle and vault around the arena instead. The Summoners are the main focus of this battle. Kill the Summoner on the bridge immediately with the chainsaw or Gauss Cannon. The next Summoner spawns immediately on the far end corner of the arena behind the tunnel. You can stun it on spawn with the Gauss Cannon. Killing the Summoners is the #1 goal. It makes this battle not too bad. Not killing the Summoners quickly turns this battle into I'd say the hardest in the entire game. Kill the Cacodemons before entering the arena. Use the same movement tactics as before, but this time use the 4x on the pillar before the big spawn up top. Get the Argent Cell behind the blue skull door. This arena is huge, and the pillars in the blood gulch are perfect for platforming and planting Holograms in a central location. Take the Haste in the low tunnel. After the battle, you'll run across an Upgrade Module. Upgrade the Gauss Cannon and fully mod it if you can. You'll come across the first Baron of the game fighting lesser demons. There are four Barons that spawn here, because this level is ridiculous. After you kill the first two Barons, kill the surprise circle Lost Souls with Remote Detonation or Micro Missiles (then drop a hologram) and immediately run for the 4x by the gate to kill the two Barons. Stand far from the ledge, the Baron across the chasm can actually jump across and warp smash you. Heat Blast under 4x can take care of these last two Barons instantly. There's a secret Megahealth opposite the Baron's gate. After the gate opens, turn around and head into the cave under the demon statue. Pull the lever. Leave the cave and drop down to the right of the bridge. Turn around and head into the retro level. Press the button on the left for the pixel Megahealth.
Kill some imps in the cliff area before heading up to the run up at the end of the level. The end of the level has a run up to the teleport that demons can only approach from one blind corner. Unknown by the devs, this creates the perfect kill zone and choke point. Lay Holograms at the 3-way junction and spam rockets and Gauss Cannon shots until it quiets down. Head toward the cliff, grab the 4x, and wait for the Barons. The Barons can be taken care of easily with 4x rockets or 4x Micro Missiles. This is the easiest way to fight the final battle from my experience. It's one of the few opportunities in the game to employ a choke point tactic like this.

This is perhaps the easiest level in the game due to ample Megahealths and no hard battles. Watch out for the surprise Cacodemon at the beginning, but that's all you really need to worry about.

Argent Cells: 1
Elite Guards: 4
Megahealths: 2
Rune Trials: In-Flight Mobility, Armored Offensive
Weapons: Chaingun

When you drop into the sky bridge's interior, turn around for the Elite Guard. After speaking with Samuel Hayden, you'll come outside to a bit of chaos. Be mostly concerned about the Cacodemons that spawn in the far sky. Just a reminder that Siege Mode kills Cacodemons in one shot, so you can kill them on spawn. This one is a little risky, but you'll get it anyway if you're getting all the Elite Guards. Before the Pinky fight, there's a Megahealth outside down below the Rune Stone in the second Elite Guard tube. Use the launch pad and drift right of the rock face slightly. Double jump onto the lower ledge. The Megahealth is at the mouth of the tube. At the end right is the Elite Guard. With your full health and armor, use this as an opportunity to practice dodging and killing Pinkies. If you have Stun Bomb, freeze them and blast them in the back. Don't camp at the end of the hall, though, because Soldiers will put their area charge shots near you. Take the 4x when you come outside. There are lots of Pinkies and Revenants, so use the jump pads to spread the demons out. Elite Guard #3 is on top of the tower slumped against a box. At the bridge battle, be aware of the Cacodemons that spawn on both sides of the platform in the sky. When the battle is over, approach the bridge to trigger the Pinkies and Mancubus to open the door. Back up. I've found Micro Missiles actually kill Pinkies with splash damage effectively from the front at distance. There's an obvious Megahealth by the stairs past the gore nest. Save it. Pull the gore nest. There's a Pinky that spawns by the crane. I like to immediately chainsaw it. I've found it to be effective to just camp the stairs with holograms. The battle ends with a Baron of Hell that spawns across the gap. When the battle is over, press the control panel to lower the crane. The platform to the right of the crane is where the Upgrade Module is. This will be the last Upgrade Module you will need in the entire game, the Chaingun. Before you pull the gore nest, turn around and jump on the rock formation. On the other side is an Argent Cell. After you pull the gore nest, take the Haste and kill the Cacodemons spawning in the sky with Siege Mode. After you drop down in the elevator shaft, turn around for Elite Guard #4. All you have to do is get on the train from there.

"God rested on the seventh day. But imagine how much further along we would be if he hadn't? The UAC is committed to excellence, that's why we implemented the seven day work week. Now you can achieve greatness alongside your coworkers every day. Let's never stop achieving."

This level is one of the easiest in the game, especially with the BFG.

Argent Cells: 1
Elite Guards: 3
Megahealths: 1
Rune Trials: Blood Fueled, Intimacy is Best
Weapons: BFG

Go into the right restroom and jump into the vent in the wall. You'll drop into Elite Guard #1. There's an Argent Cell by the control panel in the next room. Outside S. Hayden's office, you'll find the first gore nest battle. This battle is actually easy if you approach it right. A lot of players stay on the lower level, making things hard for themselves. I recommend taking the Berserk right away to kill all the Imps and Mancubus. When it wears off, make your way to the third floor and drop Holograms. This spreads the demons out and makes the battle pretty easy. There's an Elite Guard at the bottom of the elevator after Hayden's office. Take the Haste and pull the gore nest. The Gauss Cannon can 2-shot Cyber Mancubus very quickly under Haste. There's a Megahealth on the far wall behind the pipes above the entrance tube. You have to backtrack a little to get high enough to jump there. Beware of the Cacodemon that spawns behind you when you get it. Keep your eye on the Lost Souls, they can get you around a blind corner. There's an Argent Cell on the left side of the canyon on the canyon wall. When you make your way up into the vents in the wind tunnel, there's a room to the left before the BFG complex that has an ammo box and an Elite Guard. When you acquire the BFG, the game presents you with a room full of Possessed, egging you on to use the BFG. Don't. Just shoot one of the barrels with something. Or, you can use this opportunity for several masteries, including Stun Bomb. This battle arena was designed to get you to use the BFG. You could technically use the BFG 6 times in this arena, because there are 3 ammo lying in the arena. Use the Quad Damage up top, and drop holograms. Since there are 3 BFG ammo in the arena, use the BFG at least 3 times for a full refill. There's a large spawn mid-battle with Cyber Mancubus and Cacodemons where you can use it to great effect. Don't ever be shy about using the BFG. After the battle, two Barons spawn. You can save your BFG ammo by Stun Bomb + Chainsawing one and killing the other, or you can take the Quad Damage if you didn't use it. A BFG shot is a safe bet, though, especially if you mastered Ammo Boost.

I would rank this level the second most difficult in the game. It's really long—so long it has a loading screen in the middle. To make it even longer, it has a boss battle afterward.

Argent Cells: 1
Elite Guards: 4 (only 1 is necessary)
Megahealths: 2
Rune Trials: Rich Get Richer, Saving Throw
Weapons: Siphon Grenade
Worthwhile Challenges: play "Demon Destruction", kill 10 demons with a single shot (BFG in the cargo hold)

After you fight the Imps by the elevator, there's a Megahealth in the ceiling vent behind the crates. Stay up high on the supports and high ledges. Drop holograms and blast the demons that spawn against the high walls. After the battle, there's a cargo box that was blown open in the gap. It contains a BFG ammo. After you kill the Imp that drops down, vault and turn around to find the Elite Guard. If you've gotten every Elite Guard up to this point, this is the last Elite Guard you need in the game, since there are no longer any upgrades that are remotely worthwhile. The labs battle is one of the few battles in the game where I've found the best course of action is to just stay put and not move around the arena. Just stay in the initial room. It has a long line of sight. Drop holograms and take the Quad Damage. The best BFG shot angle is from where you drop down to the far end wall where the Mancubus is lying down. If you try to move around in this arena you can get cornered or surprised by Security up close with nowhere to go. There's an ammo box before the Pinky door. You'll probably need it. When you force the door open, Siege Mode the Soldier and others, then make your way into the gap in the wall behind the stone tablet on the left. There's a Megahealth there. When you reenter the room, take the Haste and run around constantly, prioritizing the Pinkies. The office has a lot to stock up on. It also has the "Demon Destruction" game that you can launch for a weapon point if you needed one. This arena is a perfect circle with a difficult-to-reach terrace. Just run along the terrace in a constant circle. Double jump and rocket the demons spawning below, keeping an eye on any demon trying to cut you off ahead. Use your BFG when the big spawn happens. After you defeat all the demons in the red room, jump through the vent on the second floor room on the right to get the BFG ammo. There's also the "Saving Throw" rune trial there as well. I've left rune trial locations up to you in this guide, but this is one that is definitely worth pointing out. When you land, launch a BFG round at the far ceiling. Take the Quad Damage and Haste. Use your Holograms. Use the launch pads. Feel free to use 2 BFG rounds in this battle, or leave it with 1/3 BFG ammo. There is a BFG round in the cargo hold and a BFG round in front of the door to the Cyberdemon.

The Cyberdemon is a difficult boss. It has a few attacks that are very difficult to dodge without practice. I'll remind you that you need to practice boss battles. Activate Saving Throw and Vacuum for this one.

The Cyberdemon will cast targets all over the ground and launch rockets into the targets. Stick to the gaps between the targets or try to reach the area without targets. This is a run ender if you get hit by it. The Cyberdemon charges a beam and tracks you with it, before locking on and firing. There are ways to dodge this consistently. You can do it by strafing one way while the Cyberdemon is charging the beam and tracking you, then when the beam changes from yellow to red, change your strafing direction. You could also back strafe and Gauss Cannon away. The hurdles are jump, stand, jump. Do not double jump on the first hurdle or you'll get hit by the last two for big damage. In stage II, he'll raise walls and shoot rockets at you. This attack is difficult to not be damaged in, so BFG him before he does it. Stage I has 1 BFG round in it. Shoot 1 BFG round at the Cyberdemon and then refill. Follow up BFG shots with Siege Mode, always. Alternate between Rockets and Gauss Cannon to finish him off. You're coming into stage II with 3 BFG rounds and one in the arena for a total of 4 BFG shots. Jump the hurdles as you do damage (I use the Micro Missiles). When the walls drop, circle strafe your way to the BFG round as you jump the next set of hurdles. By the BFG ammo, pull out your BFG and BFG, Siege Mode, BFG, Siege Mode, BFG, Siege Mode, BFG, Siege Mode. The Cyberdemon should be just about dead if not dead already.

10-13 are the home stretch. If you've made it this far, you don't need that much of my guidance, just some quick info.

One nice thing about Titan's Realm is you basically can't die by falling. The Cyber Mancubus on the first set of stairs is extremely dangerous. It's really good at putting its toxic goo on the ground for you to step in since it's elevated. In Titan's Realm you can master Saving Throw in the blood-soaked room before the trap ceiling by shooting a BFG across the room after self-killing in the hall leading up to it by the Automap. Watch me mess it up in the video. Success gives you three lives every level from here on out, effectively ending any challenge of the mode. There's nothing too crazy about 10, just don't get smashed by the pillar like I actually did. Get the Megahealth in the classic level. There is a megahealth in a corridor, you should know where it is on the Automap. 11 is easy until you turn the gears. That battle ends with two Barons, so drop a hologram in the middle and use a BFG. Carefully platform. After the battle outside, grab the BFG ammo, and Haste. This trap room is very pracarious, so I run into it with Haste. You can chainsaw the baron around the corner and then face the other behind you. Then there's two Mancubus on either end. After that, there's two groups of Invisible Pinkies on either side, BFG worthy. Drop holos and mow them down with the Chain Gun. Try to go into the second phase of the Hell Guard battle with 3 BFG rounds. There's one in the hall beforehand.
The second phase of the Hell Guard battle is the only hard one. Stun the ranged guard (the one that raises its arm) and BFG the other while the ranged guard is stunned. Repeat. So much BFG ammo. You can use the BFG upwards of twelve times on this level. That makes an otherwise difficult two final battles not too bad. There is a Megahealth in the blue keycard room and a BFG in the elevator. The Vega Core arena is pretty hectic, but if you know where the BFG ammo and cores are, it's actually VERY easy with a 3-5 well-timed BFG rounds across the room. The train station battle is probably the most difficult in the game for most players on any difficulty. It's probably where the most deaths occur. Starting off with a BFG round to the far end of the room when the train enters is a good idea. Just do laps around the train station, and at some point go fetch the bottom-floor BFG ammo with the Haste when you need them. BFG shots from the bottom floor to the far ceiling work really well. A lot of demons tend to get stuck down there. If you take a bit of a detour you'll find a megahealth. The four battles of Argen't D'Nur are nothing special, other than the nerves of "this is it." If you're really nervous use Saving Throw the whole time. Beware of the surprise Cacodemons in the platforming section after the first battle. Don't take Berserks unless you need health. Use your BFG at key times and know where the extra BFGs and Megahealths are. Teleport and use the launch pads. Dropping a hologram in front of a teleport is a great strat. Try to enter the Spider Mastermind with three BFG rounds. If you approach the first arena from the left you'll find a megahealth before you drop down. Hit the skull switch door in the hall and get a megahealth.

"They promised me so much."

is legitimately hard and requires preparation. Turn on relevent runes, like Vacuum, Rich Get Richer, or Saving Throw. A good strat is to do damage to it with Rockets/Gauss until it does its first electric attack. This is a free damage moment you'll want to take advantage of. Hop up on a pillar, and unload your (hopefully mastered) Chain Gun into its face. Don't ever use the Gauss Cannon on the pillar. As for the other attacks, the laser is singlejump/duck. Don't double jump around too much because she might hop into the laser pattern while you're still in the air. When she closes in on you, turn backwards and Gauss Cannon away from her. It's possible to get cornered if you don't have this trick in your arsenal. After that first electric attack is over, hit it with a BFG, then another BFG, and another BFG, then a Seige Mode or two. Then hit it with the last two BFG ammo found on the ends of the arena (If you didn't use them). This method skips some of the harder attacks, particularly the 2nd electricity attack with barbs in the pillar. At the end when it's mangled and tries to shoot a barbed block, just blow that up or side-step it. You'll find the ending scene and credits much more rewarding and entertaining to watch this time.

"You've won. It's over. You stopped the invasion and closed the portal—but it's come at a price."

The following bullets of advice are the "big nuggets"—the main hard-learned lessons from failing over and over and over before eventually succeeding in this mode. I've done some of that failing for you. These bullet points are super valuable:

• 01-06 is the hard part.
  
• Run a parallel Nightmare campaign to practice each level once you get a deep run (06 and on)
  
• Don't stand still or walk in a straight line.
  
• Increase your FOV to around 114 (my preference). This higher FOV gives you some peripheral vision, making your reactions and evasions much better. Don't go too high on FOV or you'll misjudge how far things are away.
  
• Do not go for combat challenges after 03 Foundry unless they are super easy like "Touch the Automap." These extra challenges cloud your mind and alter your playstyle often resulting in death. They also add play time.
  
• Some masteries are dangerous and not worth it. Some of these masteries will change your playstyle and preoccupy you. A prime example is Double Trouble for the SSG. 30 double kills will likely get you killed and the benefits aren't worth it. You also probably won't get it until 07-09. Double Trouble is awesome, sure, but 30? If it were 10-15 it would be worth it, perhaps.
  
• Do not go for levers or secrets. Getting half or all secrets in a map only gives you 1 or 2 weapon points which will not make the difference in life or death. Again, they add danger and play time. It's also frustrating to repeat them after a failed run.
  
• Do not climb toward demons, generally.
  
• Do not glory kill unless you are in a dire situation. Try not to. If you love glory kills, just don't do them in traffic. Most UN players don't typically glory kill in general.
  
• Get all the argent energies. They aren't out of the way and are worth it.
  
• Teach yourself not to self-damage.
  
• Don't engage hanging Imps. They are significantly more accurate and will hit you if you approach 99% of the time.
  
• Take platforming very seriously. Doom is a platforming game, and it's the worst way to die.
  
• You need to have an individual key/button for each weapon and practice switching to any gun you think of on command. This makes you damage demons faster. Quick switching is extremely OP. More on this later.
  
• Know where Megahealths are.
  
• Know where every powerup is and the best time to use them. Berserk is not always helpful.
  
• The Hologram is OP.
  
• Bosses have to be thoroughly practiced. Check my video for all the gravestones at the Spider Mastermind. People actually die there.
  
• Play 2-3 levels at a time, max. Playing a ton of levels back to back puts you on autopilot, often resulting in dangerous play.
  
• Use and abuse teleports and launch pads.
  
• Lapping and vaulting around the arena is almost never a bad idea.
  
• Runes are worth it. Do 7.
  
• Learning how to instinctively dodge and not take damage is just as important as learning how to deal damage.
  
• Only pick 1 upgrade per weapon. You might accidentally switch mid fight and blow yourself up. Switching mods mid battle is never better than switching weapons instead.
  
• Use different rune loadouts for different moments. Vaccuum, Saving Throw, and RGR are good runes for a boss fight, but maybe not for a gore nest.
  
• You can use the Argent Energy grenade against bosses.
  
• You're going to die a lot in 01-06 so you don't dare die in 07-13.

This is a recording of one of my full Ultra-Nightmare runs. It was very helpful for me to see how a veteran runner plays and deals with certain situations. Use this video as a reference or guide.