I still remember the first time I stumbled on Doom The Dark Ages Old One while testing the popular total conversion mod with a group of friends last year. I’d spent 20 minutes clearing a crypt full of reanimated knights and shadow imps, turned a corner into a grand stone chamber, and immediately got one-shot by a void projectile I didn’t even see coming. I spent the next three hours grinding upgrades, testing tactics, and eventually taking the boss down, and I’ve helped dozens of other players beat it since then. This guide breaks down everything you need to know to take on this iconic boss without the frustrating trial and error I went through.
Doom The Dark Ages Old One Lore and Backstory Breakdown
Most players don’t realize that Doom The Dark Ages Old One has hidden weaknesses tied directly to its backstory, so taking 2 minutes to learn the lore can cut your fight time in half. The mod is set in an alternate 10th century Europe where a rogue order of knights summoned the entity to stop a plague that was wiping out 70% of the continent’s population. The deal backfired, of course, and the Old One corrupted every knight in the order, turning them into the undead enemies you fight through the mod’s campaign. It was sealed in the abbey’s lower chamber by the last remaining uncorrupted priests, until your character breaks the seal by accident while hunting a group of shadow knights. The Old One’s core design pulls equal parts from classic Doom boss mechanics and medieval European folk tales of interdimensional entities, which makes it feel far more unique than the standard demon bosses you find in most Doom mods.
Pre-Fight Prep: Gear and Builds You’ll Need to Survive
One of the biggest mistakes new players make is walking into the Old One’s chamber with the same gear they used to clear the preceding crypt levels. Standard ballistic weapons like the regular shotgun and assault rifle do 30% less damage to the boss thanks to its permanent void shield, so you’ll need to swap to the mod’s unique holy enchanted gear to deal consistent damage. You don’t need a fully min-maxed build to beat the boss, but there are a few non-negotiable items you should pick up before you trigger the fight. You should have at least 150 holy shotgun shells and 3 full charges of the holy cross ability before entering the boss chamber, even if you prefer to run a melee build.
- Fully upgraded holy shotgun with fire rate mod: deals 2x damage to void-aligned enemies like the Old One, and can take out summoned shadow knights in one shot
- 3 holy cross consumables: each dispels one of the boss’s void shield phases instantly, cutting your fight time by almost half
- Shadow resistance armor set: cuts void projectile damage by 40% so you don’t get one-shot at full health, even during the boss’s enrage phase
- 2 health overcharge potions: let you go over your max health cap for 2 minutes, ideal for surviving the boss’s random burst attacks that are hard to dodge
If you’re a more experienced player who prefers melee builds, you can swap the holy shotgun for the fully upgraded holy greatsword, which deals 3x damage to the boss’s weak point. That said, I’ve only pulled off a melee kill twice, and both runs took at least 10 attempts, so I don’t recommend it for your first playthrough. You’ll also need to spec 3 points into the dodge distance perk if you go the melee route, so you can avoid the boss’s wide sweep attacks that deal 90% of your max health in damage.
Step-by-Step Boss Fight Tactics for All Skill Levels
The Old One fight has three distinct phases, and you’ll need to adjust your tactics for each one if you want to win without wasting all of your resources. The first phase starts as soon as you step into the center of the chamber, and the boss will stay anchored to the stone altar in the middle of the room for the entire duration. It shoots void projectiles in bursts of 5, and summons 2 shadow knights every 30 seconds to attack you from the sides of the room. Most players make the mistake of focusing all their fire on the boss during this phase, but the shadow knights drop holy ammo and health packs when you kill them, so you should take them out first to stock up for later phases. During phase 1, only shoot the Old One’s exposed glowing chest plate, as all other parts of its body are fully immune to damage.
Phase 2 triggers when you get the boss down to 60% health. It will break free from the altar, start moving around the room, and shoot tracking void orbs that follow you for 10 seconds before exploding. Run in a wide circular pattern around the edge of the room to avoid its sweep attacks, and shoot the tracking orbs before they get close to you, as they deal splash damage that can take out half your health even with the shadow resistance armor. Halfway through phase 2, the boss will regenerate its void shield, so use one of your holy cross consumables to strip it instantly instead of wasting 20 seconds shooting through it.
Phase 3 triggers when the boss hits 20% health, and it’s the hardest part of the fight by far. It gains 50% damage resistance, moves twice as fast, and summons 4 shadow knights every 20 seconds instead of 2. Save your last holy cross for the start of phase 3, as it will strip the 50% damage resistance it gains when enraged. Keep running around the edge of the room, take out the shadow knights as soon as they spawn to restock on ammo, and only shoot the boss’s chest plate when you have a clear line of sight. The fight should take 3-5 minutes total if you follow these steps, and you won’t waste all of your resources in the process.
Hidden Rewards You Get for Beating the Old One
A lot of players don’t know that the Old One has multiple hidden rewards you can unlock based on how you beat the fight, and some of them are powerful enough to make the rest of the mod’s campaign feel trivial. If you beat the boss without using any holy cross consumables, you get the Old One’s void staff, a legendary weapon that shoots void projectiles that one-shot most standard enemies and doesn’t use ammo, instead charging off of every kill you get. It’s my favorite weapon in the entire mod, and I always go back to do a no-holy-cross run whenever I start a new playthrough.
If you beat the boss in under 5 minutes, you unlock the secret “Knight’s Vow” skin for your character, which gives a permanent 10% damage boost to all holy weapons for the rest of your playthrough. It’s not a huge boost, but it makes the later boss fights far easier, so it’s worth aiming for if you’re comfortable with the fight mechanics. If you find and break all 3 hidden stone seals in the boss chamber before you trigger the fight, you’ll also unlock a secret ending cutscene that explains the full backstory of the knight order that summoned the Old One, and sets up the mod’s upcoming DLC campaign. You can only get the secret ending on your first playthrough of the mod, so make sure you look for the seals before you trigger the boss fight. I missed them on my first run, and had to start a whole new playthrough to unlock the cutscene, so that’s a mistake I want to help you avoid.
Taking on Doom The Dark Ages Old One is one of the most satisfying challenges you’ll find in any Doom total conversion mod, and it’s well worth the time you’ll spend prepping for the fight. You don’t need to be a pro player to beat it, as long as you follow the prep tips and fight tactics laid out here, you’ll be taking it down on your first or second try. Don’t forget to look for the hidden seals before you start the fight, so you don’t miss out on the secret lore and exclusive rewards. If you have your own tips for beating the boss, drop them in the comments below to help other players out.
