Important Notes

Irreversible Choices & Missable Content

Doom Eternal has no branching narrative or dialogue choices that permanently lock you out of story content. However, several gameplay elements are missable on a first playthrough without prior knowledge:

Secret Encounters: Each level contains one secret encounter (gate icon) that, if completed, summons a powerful demon. Killing it awards a weapon point. If you clear the area or leave the encounter zone without finishing it, you cannot re-trigger it later in that mission. Miss it and you lose that weapon point permanently for that playthrough.

Praetor Suit Tokens, Sentinel Crystals, and Weapon Mod Points: These collectibles are spread throughout levels. If you skip a level entirely (by replaying from mission select), you can come back later. But if you miss one in a level and progress to the next, you must replay the entire level to get it. There are no shortcuts to specific rooms.

Toy and Codex Entry Trophies: Toys are purely cosmetic, but Codex entries contain lore. Some are easy to overlook in hidden alcoves. Using the in-game map (M) after completing a level shows which collectibles you missed.

Unlockable Armor Sets: Event-exclusive cosmetic sets from series (e.g., Twitch drops, pre-order bonuses) are permanently unobtainable if missed. No in-game method to acquire them later.

Battlemode Cosmetics: Some character skins and podium animations are tied to specific seasons or promotions. Once a season ends, those items may never return.

Difficulty Spikes & How to Overcome Them

Mission 3: Cultist Base – First encounter with Arachnotrons (shield, turret). Tip: Use Plasma Rifle (stun bomb mod) to disable shield, then focus-fire with Heavy Cannon.

Mission 5: Super Gore Nest – Arena with two Marauders. Extremely punishing. Tip: Keep your distance from both, use the Super Shotgun (meat hook) to close in only on one at a time. Never let both be in melee range. Use the Ballista (precision bolt) to stun Marauder when his eyes flash green.

Mission 7: Arc Complex – The first possessed Baron of Hell (blue flame). Tip: Use the Crucible sword (one-hit kill) if you have it; otherwise, freeze with ice bomb, then unload Super Shotgun + Ballista combo.

Mission 10 (Final Boss): The Khan Maykr – She constantly regenerates shields. Tip: Use the Ballista (destroyer blade) to break shields quickly. Save your BFG for the phase where she channels multiple energy balls.

General difficulty management

Enable "Daisy" cheat code (if available) for unlimited ammo in campaign after first playthrough? No, that’s not a real cheat. Use the Sentinel Armor toggle in the pause menu if you are stuck—it grants massive damage resistance (but disables achievements).

Upgrade your Praetor Suit early: prioritize Chronostrike (slow time while airborne) and Air Control (better aerial movement). These give you breathing room.

Pitfalls & Common Mistakes

Not using the Chainsaw regularly: Many new players hoard fuel. Chainsaw kills drop ammo (including from fodder demons). Always keep at least one fuel pip by sawing low-tier enemies (Imps, Gargoyles, Soldiers) to refill ammo for your main guns. Never let ammo hit zero.

Forgetting to use the Flamethrower: The flamethrower (alt-fire on Thermal gloves) drops armor shards when enemies burn. In big fights, spam it on a crowd to get armor. Armor is your health buffer; do not neglect.

Staying on the ground: Doom Eternal punishes stationary play. Use dash, double jump, and wall-climbing (on special surfaces). The skill gap is largely about movement. If you are dying repeatedly, practice circle-strafing and jumping over projectiles.

Ignoring weapon mods: Each weapon has two mods. Unlock and upgrade them early. The Heavy Cannon’s Micro Missiles mod is great for stagger damage. The Plasma Rifle’s Microwave Beam can stun lock heavy demons but leaves you vulnerable.

Over-relying on the BFG: The BFG ammo is extremely rare (max 3 shots). Use it as an "oh crap" button only on huge crowds or bosses. Wasting it on a single Mancubus is a mistake.

Playing on Ultra-Violence first time: The game’s default difficulty is "Hurt Me Plenty". Ultra-Violence is balanced for experienced FPS players. If you struggle, tone down to "I'm Too Young to Die". No shame.

Grinding Traps & Resource Management

Weapon Points: You earn them from completing missions, killing priority targets in Secret Encounters, and finding them as pickups. If you want all weapons fully upgraded, you must find most secrets. There is no XP grind—just thorough exploration.

Praetor Suit Points: Found similarly. Max suit upgrades require all 30 points. The game gives you exactly enough if you find all. Miss some and you cannot max out. Replay levels in Mission Select to grab missed ones.

Sentinel Crystals: Exactly enough to max all 3 trees (Health, Armor, Ammo). Again, miss any and you are short. Use guides for locations.

Combat Shotgun Mods: You can only have one mod active per weapon at a time, but you can switch freely once both are unlocked. No need to grind; just unlock them at the fortress.

Upgrade Points Reallocation: There is no way to refund spent points. Choose wisely. For Suit, focus on mobility and resource generation first. For weapons, pick mods that complement your playstyle.

Runes: Three rune slots; you can swap them at any time from the pause menu. Farm runes by completing Slayer Gates (master level challenges). Best runes: Seek and Destroy (air mobility), Blood Fueled (speed boost after kill), Saving Throw (survive fatal hit once per life).

Save Management & Game Glitches

Autosave Only: Doom Eternal uses a checkpoint system, not manual saves. You cannot create a save before a boss to retry. If you miss a collectible, you must replay the mission from the fortress (Mission Select).

Checkpoint Reloading: If you die, the checkpoint loads at the last arena entrance. Sometimes you lose progress on optional objective (e.g., secret encounter half-done). If a secret encounter is bugged (rare), restart the checkpoint from the pause menu.

Beating the final boss: After completing the game, you return to the Fortress of Doom with full loadout to free-roam and find remaining collectibles with fast travel. Missed collectibles are recoverable this way.

Known Glitches:

Marauder inconsistency

Gore Nest progression bug

Performance on PC

Cross-platform saves: Not supported. Your progress is tied to the platform’s account (Bethesda.net, Steam, PSN, Xbox Live, Switch).

Online Etiquette & Anti-Cheat Notes

Battlemode (2 vs. 1): This asymmetrical multiplayer pits one player as the Slayer against two demons. Be a good sport: don’t camp spawns, don’t use exploits (e.g., infinite ammo glitches). If you are destroyed, say "gg" and try again.

Anti-Cheat System (PC): Denuvo Anti-Cheat is used. It runs at kernel level. If you are privacy-conscious, be aware. Modifying game files for single-player (e.g., unlocking cosmetics) will get you banned from Battlemode. For single-player only, you can use mods but must manually disable anti-cheat? Actually, id doesn't ban for single-player mods, but avoid altering online files. Steam achievements disabled with mods, not ban.

Cheating in Battlemode: Use of aimbots, wallhacks, or speed hacks will result in permanent ban from online play. Don't risk it.

Voice Chat: In Battlemode, you can communicate with your demon partner. Keep it civil. Avoid toxic talk; it’s just a game.

Things Players Commonly Regret Not Knowing Earlier

You can customize the HUD: Go to Settings > HUD > Advanced. You can move health bar, ammo display, and even hide the compass. Many find the default cluttered.

The tutorial mission is mandatory: Even if you are a Doom veteran, the first level teaches essential mechanics (flame belch, blood punch, etc.). Skipping it leaves you unprepared.

You can replay missions with any loadout: Once you’ve found a weapon, you keep it in all replays. This helps grab missed collectibles without starting over.

The Fortress of Doom has a secret: There’s a hidden room behind a wall that glows faintly. It contains a Cheat Code that gives you infinite ammo (after collecting all six cheats). Look up locations.

Damage numbers are misleading: The displayed number is raw damage before resistances. Use the codex for accurate values.

Health is the most precious resource: Always prioritize health pickups over ammo if low. Chainsaw for ammo, flame belch for armor, glory kills for health. Master the triangle.

The Ballista is a better sniper than the Heavy Cannon: The Ballista's precision bolt deals huge damage and stuns. The Heavy Cannon scope is weak for heavy targets.

You can quick-swap weapons: Bind two weapons to adjacent keys (PC) or use weapon wheel. Quick-swapping between Super Shotgun and Ballista maximizes DPS on stunned enemies.

Enemy weak points matter: Shoot Arachnotron’s turret, Mancubus’s arm cannons, Revenant’s shoulder pods, Cacodemon’s mouth (when it charges). This staggers or disables them. Learn each demon’s weak point.

Platforming sections are part of the game: Some players hate them. You cannot skip. Use dash + jump. If you fall, you respawn automatically at the start of the segment.

Warnings

Id Software’s Anti-Cheat: It was controversial at launch for being always-on. It still runs when playing single-player. Disconnecting from the internet does not bypass it; it will still process. If you mod, be careful.

In-game purchases: Doom Eternal has no microtransactions for gameplay. But there are paid cosmetic packs for Battlemode and single-player. They are purely visual.

Denuvo DRM: The game ships with Denuvo DRM on PC. Some players report performance impact (0-5% FPS loss). It is unlikely to be removed.

No official mod support: Unlike the original Doom, this is closed. Modding is possible but unsupported and may trigger anti-cheat.

By keeping these notes in mind, you’ll avoid many frustrations and maximize your enjoyment of the rip-and-tear experience.