- Krist's full name is Sebastian Doyle Krist, and one of the music tracks is titled "Run Like Smeg". Similarly, entering the console command "Nodnol" would cause the level to go foggy. A couple Dopefish also show up.
In the remake:
- The Triad Enforcer in the reboot enjoys listening to Anti-Flag.
- A half-spider centaur thing that fires purple homing projectiles.
- Completing the game with Lorelei nets you the "Shadow Warrior" achievement.
- Getting enough kills with the Firebomb nets you the Nukem achivement.
- Similarly, getting kills with the dual pistols is called Tequila.
- The Flamewall's alternate fire is explicitly likened to by the devs as a needler, firing glowing-hot homing needles that rip the victim to shreds.
- Trying to return to the main menu in-game gives you a yes/no prompt which asks you "Are you serious?"
- The achievement for getting 5 kills at once with an explosive or magic weapon is called Raining Blood.
- Collecting 10 coins within 5 seconds gets you the "I'm a plumber by trade" achievement, complete with an 8-bit picture that very closely resembles Mario.
- In addition, the achievement icon for getting your first Shroom looks like one of the mushrooms from Super Mario Bros., the overworld is reminiscent of the Super Mario Brothers one, and the achievement for finding all secret levels is called WARP ZONED (whose icon is a totally not Meat Boy in reference to his game's secret levels; in other words, a shout-out to a shout-out.).
- The icon for the Rocket Scientist achievement looks suspiciously like Gordon Freeman.
- The achievement for killing 666 enemies in Dog Mode is called "You're the dog now, man!"
- Killing 666 enemies with the Dark Staff gets you the achievement "You shall not pass!"
- The achievements "Hot Blooded" and "Double Vision". The former requires 666 kills with the Heat-Seeker; the latter requires 666 kills with the Split Missile.
- Beating the game with Thi Barrett earns the Red Haired Redemption achievement.
- There's an achievement named "Holy Shit" for running the game on maximum graphic settings, whose icon is the Unreal Engine logo. This is a reference to an Easter Egg in Unreal Tournament 2004 where jacking up all of its graphic settings to the max will make the announcer say "Holy shit!"
- In addition, turning all the graphic settings in ROTT 2013 to max will play an audio clip of Thi saying "Holy Shit!"
- A random prisoner in E2L4 says "I have to tell them. Priest Porridge is made of people! It's people!!!"
- The name of the second section in E1L3 is I Never Asked for This.
- The blade maze in E1L4 is named Blade Runner.
- The last part of E2L2 is Too Old for This Shit.
- E3L4 is called Clear and Present Dangers both in the original and the remake. And one area is named Harrison Fjord.
- In addition, you get a rolling rock that calls to Indiana Jones.
- The first part of E4L2 is No Remorse.
- Disabling gore bags the Grandma's Boy achievement.
- One of the loading texts is "Initializing PC Master Race".
- Thi will sing the Batman theme from The '60s on occasionally getting the Excalibat.
- When confronted by the spinning jump puzzle in E3L3, Thi will sound off with Engineer's 'nope'.
- For the mission breifing for E2L3, HQ gets distracted and says, "Mmm, donuts..."
- For the mission briefing for E3L1, HQ says, "I don't think those robots follow the three laws of robotics."
- The mission briefing for E4L2 has HQ tell you to "Suck it up, Blasckowicz had to eat dog food in Germany."
- Mecha-Hitler appears on the left side of the map screen of Episode 4.
- A switch in Sebastian Krist's boss level reveals DOOM: Repercussions of Evil written on a wall.
- Krist will say "Bazinga" when confronting you.
- Some of the areas in the remake's levels are named after other levels from the original game, such as the "Corpseyard" section of episode 1 level 2 (named after a multiplayer level from the original game). There are even references to the extra levels from the obscure Lasersoft version of the shareware episode.
- Practically everything about the Doomstick is some sort of reference to Evil Dead, from the initial reveal having a poster of Army of Darkness with ROTT characters, to quotes form the movie used in the release trailer.
- After defeating El Oscuro's first form, he will say "This isn't even my final form!" while retreating.
- When picking up the Excalibat, Lorelei says "Expecto Patronum!"
- One of the prisoners doing pushups says "Harder, better, faster, stronger..."
- Some of the Computer Screens show MS-DOS prompts showing the DIR /W output of the original ROTT game install folder c:\ROTT See here
- Some of the Hidden Rooms have pictures of classic ROTT levels or are made using the old game's graphics.
Ludicrous Edition:
- The launch trailer has a couple of clips from Civvie11's Extreme Rise of the Triad review, including his Enforcer dance party.
- The ending of The HUNT Continues depicts El Oscuro posing like the angry Wojak trying to sleep◊.
