The DOOM series has an interesting history with Dungeons & Dragons. The story of the original game has its genesis in a particularly memorable D&D campaign once played by iD Software that ended in a demonic invasion, and the now-iconic Cacodemon owes its design inspiration to the D&D expansion book Manual of the Planes.
It's no surprise, then, that playing the Doomguy himself within a D&D campaign is such a tantalizing prospect and fairly easy to pull off. This particular guide will be looking at the modern version of the character, also known as the Doom Slayer (or simply the Slayer), using only officially published D&D content.
Destruction and battle are second nature to the Doomguy, so it stands to reason that both Strength and Constitution should be the central focus. The slayer has been slaughtering demons for years and cannot be bested, only being slowed by imprisonment in his coffin. Dexterity is also a key component due to Doomguy's agility with dashes and double jumps, as well as the acrobatic nature of several of his glory kills. While the character is hardly known for winning over his foes with eloquent speeches, Charisma can be used for Intimidation checks, allowing the Doomguy to stare daggers at people standing in his way.
As for skills, Intimidation, Athletics and Acrobatics are the keys to translating both the slayer's intense aura and frantic, unrelenting power.
Doomguy's Class
The Paladin is one solid choice for the Doomslayer's class, encapsulating his eternal war against the forces of evil. They have access to both Athletics and Intimidation and the ability to sense fiends or the undead with the Divine Sense feature, and the class's Divine Smite is an excellent representation of DOOM Eternal's blood punch mechanic.
The other choice for class is unsurprisingly a Barbarian; like Doomguy, they are defined by fury and violence. The Barbarian is able to enter a rage as a bonus action, and once they gain Persistent Rage, it will end only when they fall unconscious. Combining this with the Berserker subclass will suitably mimic the character's bloodlust.
Background, Race and Alignment
The Doomslayer's race is a simple choice; despite his supernatural strength and endurance, he is still a human. The character's background should be Soldier, as The Doomguy was originally a U.S. Marine before he was dishonorably discharged after refusing to fire on unarmed civilians. Mechanically, Humans gain an additional point to all of their ability scores, and the Soldier is proficient in both Athletics and Intimidation.
Lastly, the Doomguy's moral alignment is certainly Chaotic Good. He takes whatever actions he believes to be right, regardless of the consequences or opinions of others.
Equipment
The slayer is a versatile warrior capable of utilizing both powerful ranged weapons and brutal melee ones. The Barbarian is capable of starting with any martial melee weapon. Choosing the Longsword to represent his DOOM Eternal Crucible is one option, and a Warhammer can also be selected to embody The Ancient Gods Part 2's Sentinel Hammer. The Paladin is also capable of beginning with a martial weapon and a shield or, more fittingly, two martial weapons, allowing Doomguy to begin the campaign with both his trusty Crucible and Sentinel Hammer.
That said, much of Doomguy's strength stems from his versatility in combat, meaning this build could realistically utilize a great array of weapons when necessary.
Final Touches
The key features of an accurate Doomslayer build have now been established at this stage, so this build should be close to completion. One difficulty may be justifying the character's potential teamwork within the party, as the slayer very rarely works alongside others. The player may even use this to their advantage, creating some interesting dynamics within the group as Doomguy occasionally does as he sees fit, even if it means faltering the party.
This Doomguy character build will function as a powerful, unrelenting warrior of rage within any campaign. If a sudden demonic invasion halts a D&D adventure much the same as iD's was all those years ago, a Doomslayer is well equipped to rip and tear until it is done.