Cheating in video games has a long and storied history. Though today the term is usually synonymous with software hacking or utilizing third party peripherals (such as a lag switch), the original and most basic cheats came in the form of codes that were built into the game for playtesting purposes.
Such is the case with DOOM, the grandfather of practically every first person shooter on the market. Chances are that every gamer of its generation knows exactly what "IDDQD" means, but a refresher course might be in order for those replaying the original demon murder simulator to get hyped for DOOM Eternal. Below are the ten most useful cheat codes to keep in mind in the event of a portal to hell opening on Mars. While the PC codes are what's being focused on, there are equivalents for most of them on DOOM's many console ports.
10 Gain Invisibility
It might not be the most useful cheat on the list, but it's definitely a handy shortcut to getting an incredibly useful power up at the right time when attempting to avoid the temptation to engage all-out god mode.
idbeholdi will grant the player an invisibility sphere, rendering them a shadowy outline that foes will often miss when attacking. It doesn't render them totally invisible, but it's enough to make tough encounters with tons of ranged demons and zombies manageable.
9 Change The Level Music
idmusxx swaps the level music for the music attached to the stage of the player's choosing, when "xx" is replaced by the corresponding level. For example, if the player wants to play the music from level fourteen in DOOM II, they'd end up typing idmus14.
While the change is entirely superficial, the short loops of digitized instrument ensembles can grate at the nerves when players are stuck on a particular level for an extended period of time. This cheat can provide some much needed relief when DOOM's rendition of Pantera's Mouth For War rolls around for the nine billionth time.
8 Get The Chainsaw
For a lot of players, this code is the only thing they'll ever need. DOOM's chainsaw is an iconic and ridiculous weapon that has persisted throughout the entirety of the series' lifetime, in all of its gloriously gory absurdity.
Typing the aptly worded idchopppers will grant players the chainsaw outright, skipping all of the nonsense involved with actually progressing through a level and locating one for themselves. After all, enemies killed while looking for a chainsaw are ultimately enemies that weren't killed with a chainsaw, and that's just wasted potential.
7 Upgrade The Map
For players that just need a little help figuring out where to go next or remembering a level's layout, this set of codes should give them a push in the right direction. Both idbeholda and iddt will give the in-game map a much needed boost.
idbeholda simply gives players the computer area map power up, filling in their map's unexplored areas. iddt goes a little more in depth, revealing some hidden details on the map that aren't accessible by conventional means, such as actor locations.
6 Instant Berserk Mode
Finding a berserk power up in the old school titles may not be quite as viscerally satisfying as it is in the 2016 reboot of the series, but it still guarantees a few moments of ludicrously gory mayhem as the player waltzes around and punches enemies into a pile of giblets.
idbeholds allows players to access this power up whenever they want. With just a few keystrokes, the entire game basically turns into an incredibly dark and exponentially more violent take on Punch-Out.
5 Radiation Shielding
Sometimes, the player's going to need to wade through a pile of snotty green goop that saps away at their health in order to progress or reach a secret area stuffed full of ammo, guns and other good things. The issue is that they might've already wasted the radiation suit meant to protect them, if there was one there to begin with.
idbeholdr is the less than legitimate remedy for that situation, immediately granting the player the immunity they need to brave the nuclear waste. Or perhaps they just want that neat green-tinted effect it has on the screen for immersion purposes.
4 No Clipping
Nobody likes walls. They impede progress, conceal secret areas, or otherwise indicate to the player, "You can't go here." And if there's anything the player hates, it's being told that they're expressly not allowed to go somewhere.
But in DOOM, they can really show that wall who the boss is by ignoring them. So long as they type in idclip or idspispopd first, they can break the laws of physics by stepping through walls as if they never existed! This does present some quirks though, such as being able to walk endlessly into the void surrounding every level. Interestingly, using this cheat is the only way to reveal DOOM II's hidden boss, developer John Romero.
3 Warp To Any Level
While most launchers have the functionality to allow players to start on any stage they choose, this one's still handy for jumping around without having to shut off the game. idclevxx (with xx being the desired map) will do put the player on any desired stage, even the secret levels.
While this one's largely absent from console ports, some of them still have a workaround by having an "end level" cheat code that will advance them to the next map.
2 Gain All Weapons, Full Ammunition, And Keys
This cheat sets players up for the essential DOOM experience, gearing them up with all of the weapons in the game, all the ammunition they can carry, full armor, and all the keys they'll need to progress. If hosting an unimpeded, non-stop lead-and-rocket giveaway is what's desired, entering idkfa is the way to do it.
It should be noted that this one can be reentered as many times as needed, in the event that players need even more bullets. Hilariously, in lesser known DOOM clone Heretic, this code will take away the entirety of the player's inventory.
1 God Mode
Finally, the mother of all cheat codes, present in practically every game that has ever actually had cheat codes (and some that don't): god mode. Typing in iddqd will render the player totally immune to harm, with the Doom Guy's portrait adopting shining golden eyes to reflect his newfound omnipotence.
This in combination with the all weapons cheat engages the ultimate power fantasy a la DOOM. Conversely, if this code is entered in the cult classic DOOM clone Heretic, it'll actually instantly kill the player.