DERP v0.7.666

What's new in v0.7.666

The big one. Everything since v0.7.4: a whole climate, weather that
moves and gets moved, a new episode, Phobos in the main build, tunnels that
sound like tunnels, and a long list of smaller things. As always, nearly
all of it is drawing and sound only: the game, its damage and its demos are
unchanged unless a note says otherwise.

A new episode

Episode 0.5: SCP_7179_B. A new entry in the episode menu when you play
DOOM II, TNT or Plutonia. That is all we are going to say about it.

Climate

Pick the weather, the time of day, the temperature and the wind.
F4 → Game → Mode → Weather. Each one is the map's own or a single choice for
every map:

• Weather: Clear, Rain, Snow, Nukage rain, Sand, Ash, Fog or Dry ice.
• Time of day: Dawn, Morning, Noon, Afternoon, Dusk or Night.
• Temperature: -30 °C to 50 °C.
• Wind: Still, Breeze, Strong or Gale, from any of eight directions.

The menu never offers a combination that doesn't fit: no snow at 40 °C, no
sandstorm in still air, no fog in a gale, no 50 °C at night. Choices follow
the menu's order, so the weather is always all there and a clash moves the
choices below it to the nearest one that fits. Real heat bleaches the sky,
raises a warm haze and shimmers the far ground.

Snow. Flakes a pixel wide drift under the sky and blow in through broken
windows. The ground lies white in ragged drifts, deeper the harder it falls,
scoured into long streaks and deep drifts in a gale. Windows frost from
their edges in. Out in the snow the echoes fade and dull.

Blizzards. Hard snow in a hard wind turns into a blizzard: flakes
streaking edge to edge, thicker far sheets, and a whiteout that swallows
everything within a few hundred units. Open ground lights evenly in it, the
sky pales toward the horizon, and the whiteout eases in and out at doorways.

Sand and ash. Sandstorms with a dust haze, grains that skip and roll in
crowds, and ripples creeping downwind. Ash is volcanic: dark grey, with
glowing embers. Both pile up indoors where they blow in.

Fog and dry ice. Fog lies smooth. Dry ice lies banded and heavy, pours
down steps, fills the low streets and pits, creeps in at windows and doors
and leaves walkways and rooftops clear. A hot thing or a blast boils a hole
into either, and the bank fills back in from the edge.

Water freezes. Below freezing, water ices over map cell by map cell,
following the air's temperature in each room and drafts from outside, and
gathers into floes. Steps on it sound like stone; it has its own sounds.

The wind is heard. Past a breeze it never lets up: a low roar runs
under the gusts and buffets a few times a second.

Weather that moves

Rooms and drafts. At level load DERP works out which sectors make up a
room, which are openings (doors, windows, recesses) and which are porches.
Air flows through the openings, rooms keep their own temperature, and what
falls outside is carried indoors along the drafts: snow trails, slush,
rime round cold inlets, sand fingering in from a doorway.

The air pushes what flies. Gusts roll across open ground and shove every
flake, drop and grain. Indoors a draft's jet stirs what rides it, tight at
the opening, swirling where it turns.

Things disturb the weather. Rockets, barrels and BFG balls shove what
flies, blow the indoor drifts into a ragged rim, punch holes into fog and
throw up a puff of whatever lay there. Projectiles leave wakes, bodies land
in puffs, footsteps leave prints, bullets kick the floor, slamming doors
breathe out. Torches and anything burning are hot spots: snow melts round
them and the fog boils away.

The ground keeps the dents. Outdoors, craters and prints stay in the
snow, sand and ash and fill back in as more falls or the wind blows.

Blown in. What comes through a broken window keeps flying the way it
flew outside, then slows indoors. Doorways opened during play lay snow and
rain in front of them as broken windows do. Powder snow settles loosely
and drifts on in the gusts.

Clear costs nothing. With Clear weather the drafts, rooms and ground work
are all skipped; the wind is only heard.

Light

One light rule. Sun and sky light now follow a single rule on how much
of the sky each surface really sees, blended across the seams, so nothing
steps where a roof ends. Holes in a roof shade at the room's level, and
sunbeams rise from the whole sun patch, porches included.

The flashlight lights the weather. Flakes, drops and grains in the beam
light up, the cone shows in snow, sand and ash, fog and dry ice glow where
it passes, and lying snow and sand glitter.

Soft shot shadows. Muzzle flashes, projectiles and burning barrels cast
shadows whose edges step with the artwork and soften like the baked ones.
F4 → Graphics → Lighting → Flashlight and shadows, on by default.

Metal shading. Bare metal takes highlights in its own colour, and
mostly blank plates get a brushed sheen running the way the artwork's
streaks do. F4 → Graphics → Surface detail.

Faster lights and bakes. Worst views on E1M1 and E1M2 are 1.1 to 1.85 ms
faster on the GPU; bakes and door re-bakes are faster on the CPU.

Sound

Tunnel acoustics. Long narrow passages ring like sewers: a longer tail,
flutter between the side walls (more over water), and no echo coming back
off the far end. Rooms that are no tube sound exactly as before, minus a
small click on big reverb changes that is gone everywhere.

Phobos

Physically accurate Phobos is in the main build. The v0.7.4-phobos
experiment, DOOM's first episode on a moon 22 km across, in vacuum, with
gravity at 1/1700 g, now comes with every download. Pick Phobos for
Gameplay in F4 → Game → Mode; its options are on F4 → Game → Phobos.
Off by default, never in demos or netgames. New since the experiment:

• Grav boots: walk on floors and ceilings; the view rolls over onto the
  ceiling as you pass the middle of the room.
• The sky is no lid: you and your rockets go up until about 900 m.
• F4 → Game → Mode → Gameplay is one choice, Normal / Authored / Phobos,
  so the authored looks and Phobos never mix.

Game and controls

Normal plus movement. F4 → Game → Controls → Movement is now Normal,
Normal plus or Classic. Normal plus keeps the tight starts and normalized
diagonals, but a running diagonal held for a moment builds up to DOOM's full
strafe-running. Demos and netgames stay classic.

Missiles fly down the crosshair. With free aim, your rockets and plasma
leave from the eye and fly along the view's pitch, as bullets do.

Enemy-appropriate blood. Cacodemons bleed blue, Barons of Hell and Hell
Knights green, Lost Souls not at all, everyone else red. Splats, spray,
pools and wound rims follow. F4 → Graphics → Combat → Blood.

"Picked up a mag." The pistol's ammo pickup no longer claims a clip.
DeHackEd patches still win.

Ragdolls fly further. A body thrown far picks up the walls and floors
round where it flies instead of dropping dead at the edge of what it knew.

Display

F4 is grouped. Game, Graphics and Sound sit above the tabs; Tab steps
through every page and PgUp/PgDn switch groups.

Show FPS. F4 → Graphics → Display: Off, In the window title, FPS, or
Full, with a frame-time graph, where the time goes, and the systems at work.
The key left of 1 cycles it. Handy for screenshots in bug reports.

Frame presentation. VSync, VSync with 3 frames, Fast, Adaptive or Off,
with a frame limit for the uncapped ones.

Window size. Set the window to exactly 1280x720 up to 3840x2160, for
recordings and screenshots at a known size. Free is the default.

Skip hidden walls and floors. A new Performance switch (off by default)
leaves out geometry hidden behind solid walls and closed doors.

Smoother over long sessions. The drawing clock no longer loses precision
after days of play, so fog, weather and water stop stuttering in very long
sessions.

Downloads and maps

Play DERP everywhere. On Windows the program is now Play DERP.exe
with the DERP icon; on Linux it is play-derp with its own window icon.

DERPINFO. Mappers can set a map's climate, sky, sun, fog and more with
a DERPINFO lump. See DERPINFO.md.

Sky fix for every map. Sky sectors joined by an open line share the
highest sky, as vanilla shows them: E1M1's south yard no longer slices its
walls off.

DERP, the DOOM Engine Remaster Project. Each download includes Freedoom, so you can
play straight away; add your own WADs to play DOOM, DOOM II, Heretic or custom maps.

Download

System	File	How to play
macOS 11 or newer (Apple Silicon and Intel)	DERP-mac.zip	Unzip and open Play DERP.app. Choose your WAD folder or click Play Freedoom.
Windows 10/11, 64-bit	DERP-windows.zip	Unzip, drop your .wad files into the wads folder and run Play DERP.exe.
Linux, x86-64	DERP-linux.tar.gz	Unpack, drop your .wad files into wads and run ./play-derp.

DERP-source.tar.gz is the complete source of these downloads: the
game's code plus the exact SDL and Nuked OPL3 sources it is built with, so it
builds without an internet connection. GitHub's "Source code" archives hold
the game's code only.

With no WADs in the wads folder, Freedoom starts. With a base game (such as
doom.wad or doom2.wad) and a custom map WAD, the map is loaded on top of the
game. Controls and options are in PLAY.md.

macOS: the app is not notarized by Apple, so the first launch is blocked
with "Apple could not verify…". Click Done, open System Settings → Privacy &
Security, scroll down and click Open Anyway next to the message about
Play DERP, then confirm. After that it opens normally. (Alternatively, run
xattr -dr com.apple.quarantine "Play DERP.app" in Terminal.)

Windows: the program is not code-signed, so SmartScreen may say "Windows
protec...

DERP v0.7.666-hotfix

What's new in v0.7.666-hotfix

A hotfix for v0.7.666. The same game with three fixes. If v0.7.666
runs fine for you, there is no need to update.

Windows: user names with non-Latin letters. If your Windows user name
(or the folder DERP sits in) has letters such as é, ü or Cyrillic, DERP
asked for a WAD file even though Freedoom is included, and then closed
without a word. It now finds its files and its save folder on any path.
Windows 10 version 1903 or newer.

Windows: a message instead of silence. If the game cannot open its
save folder, it now says so and shows the folder, instead of closing
without one.

Heretic: a crash at startup. Heretic could crash while loading its
sprites, depending on the build. This came from the original 1990s code,
which only worked as long as the memory after the sprite list happened to
be empty.

DERP, the DOOM Engine Remaster Project. Each download includes Freedoom, so you can
play straight away; add your own WADs to play DOOM, DOOM II, Heretic or custom maps.

Download

System	File	How to play
macOS 11 or newer (Apple Silicon and Intel)	DERP-mac.zip	Unzip and open Play DERP.app. Choose your WAD folder or click Play Freedoom.
Windows 10/11, 64-bit	DERP-windows.zip	Unzip, drop your .wad files into the wads folder and run Play DERP.exe.
Linux, x86-64	DERP-linux.tar.gz	Unpack, drop your .wad files into wads and run ./play-derp.

DERP-source.tar.gz is the complete source of these downloads: the
game's code plus the exact SDL and Nuked OPL3 sources it is built with, so it
builds without an internet connection. GitHub's "Source code" archives hold
the game's code only.

With no WADs in the wads folder, Freedoom starts. With a base game (such as
doom.wad or doom2.wad) and a custom map WAD, the map is loaded on top of the
game. Controls and options are in PLAY.md.

macOS: the app is not notarized by Apple, so the first launch is blocked
with "Apple could not verify…". Click Done, open System Settings → Privacy &
Security, scroll down and click Open Anyway next to the message about
Play DERP, then confirm. After that it opens normally. (Alternatively, run
xattr -dr com.apple.quarantine "Play DERP.app" in Terminal.)

Windows: the program is not code-signed, so SmartScreen may say "Windows
protected your PC". Click More info, then Run anyway.

Linux: you need a Vulkan driver for the 3D renderer; without one the game
falls back to the classic renderer.

Before you play

This is a pre-release. The Mac version is the most tested. The Windows and Linux
versions are built automatically but have had little real play, so please
report problems.

Supported maps: vanilla and limit-removing, including DEHACKED patches. Boom,
MBF21 and GZDoom maps are not supported. Heretic plays from your own heretic.wad
or HERETIC.WAD; Hexen is not supported yet. Multiplayer is not implemented.

DERP v0.7.4-phobos

What's new in v0.7.4-phobos

This is a JOKE! This is DERP v0.7.4 with one
experiment on top: Physically accurate Phobos, DOOM's first episode taken
literally. The base it runs on is on Phobos, a moon 22 km across, in vacuum,
with Mars hanging in the sky. For the regular game, stay on v0.7.4.

It is on by default here and only touches the first episode (DOOM's, or
Freedoom: Phase 1's); every other map plays as in v0.7.4. Switch it off in
F4 → Physically accurate Phobos. Never in demos or netgames.

You weigh about as much as a chocolate bar. Phobos pulls at 1/1700 of
Earth's gravity, so you can't walk: your feet only grip because your weight
presses them down.

• Movement keys: gentle hops. A 30 cm hop floats for about 20 seconds.
• Use with a movement key next to a wall: kicks you off it along the
  floor at 4 m/s, the way astronauts cross a space station.
• E: a full 4 m/s jump. Leaving Phobos takes 11 m/s.
• Run with movement: fires the suit's thrusters.

Landings brake you by friction; everything else slides on.

Every shot pushes back. Recoil and knockback use real momentum: a
pistol round is about 3 N·s, a shotgun blast 16 and the super shotgun 32.
In the air your guns are thrusters. A full arsenal is about 20 m/s of
push, enough to shoot yourself off the moon. The optional F4 setting
Guns turn you also spins you, into backflips if you keep firing.

Explosive decompression. Every room holds air at Earth pressure. Shoot a
window (or open a door to the outside) and the room empties through it at
the speed of sound:

• Air: doors seal rooms and cycle like airlocks, and sealed rooms refill.
• Bodies: loose things go with the air. Monsters strain against it, then
  tear loose and tumble, while lamps stay bolted down. Bodies and barrels
  thrown at windows break them, so one breach can set off the next.

The zombies have no brains. Zombiemen and shotgun guys never learned to
move on Phobos:

• Movement: every Earth-style step throws them up into a slow tumble.
• Aim: they twist round toward you like a falling cat and fire wherever
  their arms can reach.
• Recoil: their own shots push them away.

Barrels hold 225 kg of rocket fuel. They tumble when knocked and blow up
on a crash over 10 m/s. Pickups weigh what they would, so a box of shells
is 200 g.

The vacuum shows. The sky is black space with Mars. Your visor frosts.
Blood boils and freezes, and bodies frost and swell. Nukage boils, ices over
and loses its glow. Sound only reaches you through what you touch.

DERP, the DOOM Engine Remaster Project. Each download includes Freedoom, so you can
play straight away; add your own WADs to play DOOM, DOOM II, Heretic or custom maps.

Download

System	File	How to play
macOS 11 or newer (Apple Silicon and Intel)	DERP-mac.zip	Unzip and open Play DOOM.app. Choose your WAD folder or click Play Freedoom.
Windows 10/11, 64-bit	DERP-windows.zip	Unzip, drop your .wad files into the wads folder and run doom.exe.
Linux, x86-64	DERP-linux.tar.gz	Unpack, drop your .wad files into wads and run ./doom.

DERP-source.tar.gz is the complete source of these downloads: the
game's code plus the exact SDL and Nuked OPL3 sources it is built with, so it
builds without an internet connection. GitHub's "Source code" archives hold
the game's code only.

With no WADs in the wads folder, Freedoom starts. With a base game (such as
doom.wad or doom2.wad) and a custom map WAD, the map is loaded on top of the
game. Controls and options are in PLAY.md.

macOS: the app is not notarized by Apple, so the first launch is blocked
with "Apple could not verify…". Click Done, open System Settings → Privacy &
Security, scroll down and click Open Anyway next to the message about
Play DOOM, then confirm. After that it opens normally. (Alternatively, run
xattr -dr com.apple.quarantine "Play DOOM.app" in Terminal.)

Windows: the program is not code-signed, so SmartScreen may say "Windows
protected your PC". Click More info, then Run anyway.

Linux: you need a Vulkan driver for the 3D renderer; without one the game
falls back to the classic renderer.

Before you play

This is a pre-release. The Mac version is the most tested. The Windows and Linux
versions are built automatically but have had little real play, so please
report problems.

Supported maps: vanilla and limit-removing, including DEHACKED patches. Boom,
MBF21 and GZDoom maps are not supported. Heretic plays from your own heretic.wad
or HERETIC.WAD; Hexen is not supported yet. Multiplayer is not implemented.

DERP v0.7.4

What's new in v0.7.4

Flying enemies. Choose F4 → Combat → Deaths → Ragdolls, Hollywood
and explosions send bodies flying. A monster killed by a rocket, barrel or
BFG blast is thrown back and up, somersaulting, glances off walls and
columns and can reach a second wall before it lands. It no longer goes to
mush: a blast that gibs a monster draws the whole body thrown instead,
while the game's blood and gib sound still play. Shots punch harder too. A
chaingun's last bullet hops the body, a shotgun throws it, a super shotgun
harder, and it spins the way it was struck: a hit off the middle turns it,
a high one tips it over backward. As before, this is drawing only; the
game, its damage and demos are unchanged.

Simpler combat settings. The row of death and blood switches in F4 →
Combat is now three choices. Deaths goes Classic, Varied, Procedural
falls, Ragdolls or Ragdolls, Hollywood. Hit reactions turns flinches
and death jolts on or off. Blood is Off, Splats or Full. Your existing
settings carry over.

Bodies splash into liquids. A body falling into water, nukage, blood or
lava heaves the surface and throws up a crown of chunky globs and a column
in the middle. A harder fall and a heavier monster throw more, higher and
wider; thick liquids throw fewer, fatter globs and water a spray of foam.
Part of F4 → Splashes.

The F4 panel shows what you changed. A small diamond marks each option
that differs from its default. Backspace resets just that one; R still
resets everything.

Quicksave without asking. A new F4 option, Confirm quicksave and
quickload (on by default). Turn it off and F6 and F9 save and load at
once, in DOOM and Heretic.

Quieter boots in the echoes. Your own footsteps, splashes and gear keep
their direct sound but put much less into the room's reverb (about 7 dB
less when walking), so quiet movement stays quiet. Steps on metal floors
now sound like a rubber sole on solid steel, a short metallic edge rather
than a hollow ringing deck.

Launchers with mods. Launchers hand every enabled mod to every port. A
.pk3 archive, or a lump file whose name is longer than 8 characters, is now
skipped with a note instead of stopping the game.

Grey concrete stays matte. DOOM's grey concrete walls, columns and
steps, and the floors and ceilings that go with them, no longer shine like
steel.

DERP, the DOOM Engine Remaster Project. Each download includes Freedoom, so you can
play straight away; add your own WADs to play DOOM, DOOM II, Heretic or custom maps.

Download

System	File	How to play
macOS 11 or newer (Apple Silicon and Intel)	DERP-mac.zip	Unzip and open Play DOOM.app. Choose your WAD folder or click Play Freedoom.
Windows 10/11, 64-bit	DERP-windows.zip	Unzip, drop your .wad files into the wads folder and run doom.exe.
Linux, x86-64	DERP-linux.tar.gz	Unpack, drop your .wad files into wads and run ./doom.

DERP-source.tar.gz is the complete source of these downloads: the
game's code plus the exact SDL and Nuked OPL3 sources it is built with, so it
builds without an internet connection. GitHub's "Source code" archives hold
the game's code only.

With no WADs in the wads folder, Freedoom starts. With a base game (such as
doom.wad or doom2.wad) and a custom map WAD, the map is loaded on top of the
game. Controls and options are in PLAY.md.

macOS: the app is not notarized by Apple, so the first launch is blocked
with "Apple could not verify…". Click Done, open System Settings → Privacy &
Security, scroll down and click Open Anyway next to the message about
Play DOOM, then confirm. After that it opens normally. (Alternatively, run
xattr -dr com.apple.quarantine "Play DOOM.app" in Terminal.)

Windows: the program is not code-signed, so SmartScreen may say "Windows
protected your PC". Click More info, then Run anyway.

Linux: you need a Vulkan driver for the 3D renderer; without one the game
falls back to the classic renderer.

Before you play

This is a pre-release. The Mac version is the most tested. The Windows and Linux
versions are built automatically but have had little real play, so please
report problems.

Supported maps: vanilla and limit-removing, including DEHACKED patches. Boom,
MBF21 and GZDoom maps are not supported. Heretic plays from your own heretic.wad
or HERETIC.WAD; Hexen is not supported yet. Multiplayer is not implemented.

DERP v0.7.3

What's new in v0.7.3

The Steam and GOG game files work properly. The DOOM, DOOM II, TNT and
Plutonia files sold today (the 2019 and 2024 re-releases) carry widescreen
versions of the title pages, help and credit screens, intermission maps,
end screens and status bar. DERP skipped these wider pictures, so the
title screen stayed black with menu pages piling up on top of each other,
and the status bar lost its grey background (issue #18). They are now
drawn centered, showing the classic 4:3 middle. The episode 3 ending's
scrolling picture lines up again too. The original DOS files were not
affected.

DERP, the DOOM Engine Remaster Project. Each download includes Freedoom, so you can
play straight away; add your own WADs to play DOOM, DOOM II, Heretic or custom maps.

Download

System	File	How to play
macOS 11 or newer (Apple Silicon and Intel)	DERP-mac.zip	Unzip and open Play DOOM.app. Choose your WAD folder or click Play Freedoom.
Windows 10/11, 64-bit	DERP-windows.zip	Unzip, drop your .wad files into the wads folder and run doom.exe.
Linux, x86-64	DERP-linux.tar.gz	Unpack, drop your .wad files into wads and run ./doom.

DERP-source.tar.gz is the complete source of these downloads: the
game's code plus the exact SDL and Nuked OPL3 sources it is built with, so it
builds without an internet connection. GitHub's "Source code" archives hold
the game's code only.

With no WADs in the wads folder, Freedoom starts. With a base game (such as
doom.wad or doom2.wad) and a custom map WAD, the map is loaded on top of the
game. Controls and options are in PLAY.md.

macOS: the app is not notarized by Apple, so the first launch is blocked
with "Apple could not verify…". Click Done, open System Settings → Privacy &
Security, scroll down and click Open Anyway next to the message about
Play DOOM, then confirm. After that it opens normally. (Alternatively, run
xattr -dr com.apple.quarantine "Play DOOM.app" in Terminal.)

Windows: the program is not code-signed, so SmartScreen may say "Windows
protected your PC". Click More info, then Run anyway.

Linux: you need a Vulkan driver for the 3D renderer; without one the game
falls back to the classic renderer.

Before you play

This is a pre-release. The Mac version is the most tested. The Windows and Linux
versions are built automatically but have had little real play, so please
report problems.

Supported maps: vanilla and limit-removing, including DEHACKED patches. Boom,
MBF21 and GZDoom maps are not supported. Heretic plays from your own heretic.wad
or HERETIC.WAD; Hexen is not supported yet. Multiplayer is not implemented.

DERP v0.7.2

What's new in v0.7.2

Invert mouse look. A new F4 option under Display → View, shown while
Mouse look is on: pushing the mouse forward tilts the view down, like a
flight stick. Off by default. It works in DOOM and Heretic and is saved
with the other graphics settings.

DERP, the DOOM Engine Remaster Project. Each download includes Freedoom, so you can
play straight away; add your own WADs to play DOOM, DOOM II, Heretic or custom maps.

Download

System	File	How to play
macOS 11 or newer (Apple Silicon and Intel)	DERP-mac.zip	Unzip and open Play DOOM.app. Choose your WAD folder or click Play Freedoom.
Windows 10/11, 64-bit	DERP-windows.zip	Unzip, drop your .wad files into the wads folder and run doom.exe.
Linux, x86-64	DERP-linux.tar.gz	Unpack, drop your .wad files into wads and run ./doom.

DERP-source.tar.gz is the complete source of these downloads: the
game's code plus the exact SDL and Nuked OPL3 sources it is built with, so it
builds without an internet connection. GitHub's "Source code" archives hold
the game's code only.

With no WADs in the wads folder, Freedoom starts. With a base game (such as
doom.wad or doom2.wad) and a custom map WAD, the map is loaded on top of the
game. Controls and options are in PLAY.md.

macOS: the app is not notarized by Apple, so the first launch is blocked
with "Apple could not verify…". Click Done, open System Settings → Privacy &
Security, scroll down and click Open Anyway next to the message about
Play DOOM, then confirm. After that it opens normally. (Alternatively, run
xattr -dr com.apple.quarantine "Play DOOM.app" in Terminal.)

Windows: the program is not code-signed, so SmartScreen may say "Windows
protected your PC". Click More info, then Run anyway.

Linux: you need a Vulkan driver for the 3D renderer; without one the game
falls back to the classic renderer.

Before you play

This is a pre-release. The Mac version is the most tested. The Windows and Linux
versions are built automatically but have had little real play, so please
report problems.

Supported maps: vanilla and limit-removing, including DEHACKED patches. Boom,
MBF21 and GZDoom maps are not supported. Heretic plays from your own heretic.wad
or HERETIC.WAD; Hexen is not supported yet. Multiplayer is not implemented.

DERP v0.7.1

What's new in v0.7.1

Works from launchers. Launchers such as Doom Runner start the game with
paths relative to its folder, like ..\..\Game IWADs\DOOM2.WAD. DERP moved
to its save folder before opening them, so the game stopped with "Not a
valid game IWAD". The IWAD, add-on files, DEHACKED patches, config file,
SoundFont and demo recording paths now work however the launcher writes
them. In Doom Runner, pick the PrBoom engine family and point the data
directory at %APPDATA%\Local Games\DOOM to see DERP's saves.

DERP, the DOOM Engine Remaster Project. Each download includes Freedoom, so you can
play straight away; add your own WADs to play DOOM, DOOM II, Heretic or custom maps.

Download

System	File	How to play
macOS 11 or newer (Apple Silicon and Intel)	DERP-mac.zip	Unzip and open Play DOOM.app. Choose your WAD folder or click Play Freedoom.
Windows 10/11, 64-bit	DERP-windows.zip	Unzip, drop your .wad files into the wads folder and run doom.exe.
Linux, x86-64	DERP-linux.tar.gz	Unpack, drop your .wad files into wads and run ./doom.

DERP-source.tar.gz is the complete source of these downloads: the
game's code plus the exact SDL and Nuked OPL3 sources it is built with, so it
builds without an internet connection. GitHub's "Source code" archives hold
the game's code only.

With no WADs in the wads folder, Freedoom starts. With a base game (such as
doom.wad or doom2.wad) and a custom map WAD, the map is loaded on top of the
game. Controls and options are in PLAY.md.

macOS: the app is not notarized by Apple, so the first launch is blocked
with "Apple could not verify…". Click Done, open System Settings → Privacy &
Security, scroll down and click Open Anyway next to the message about
Play DOOM, then confirm. After that it opens normally. (Alternatively, run
xattr -dr com.apple.quarantine "Play DOOM.app" in Terminal.)

Windows: the program is not code-signed, so SmartScreen may say "Windows
protected your PC". Click More info, then Run anyway.

Linux: you need a Vulkan driver for the 3D renderer; without one the game
falls back to the classic renderer.

Before you play

This is a pre-release. The Mac version is the most tested. The Windows and Linux
versions are built automatically but have had little real play, so please
report problems.

Supported maps: vanilla and limit-removing, including DEHACKED patches. Boom,
MBF21 and GZDoom maps are not supported. Heretic plays from your own heretic.wad
or HERETIC.WAD; Hexen is not supported yet. Multiplayer is not implemented.

DERP v0.7.0

What's new in v0.7.0

Heretic is in the downloads. v0.5.0 and v0.6.0 announced Heretic, but
their packages left the derp-heretic program out, so Heretic WADs had
nothing to start. It now ships in every package: beside the game on Windows
and Linux, inside the app on the Mac.

Ragdoll falls. Monsters on two legs can now drop as ragdolls. Each one's
drawing is raised into a body as deep as its side view shows, on a small
skeleton that the killing blow knocks over. It can be thrown back, have its
legs swept, be spun from the side or have its strings cut by a head shot.
The body comes to rest on its back or side, drawn the way its own sprite
sees it. With Shot deaths on strings, a chest blast from the front
sometimes plays the zombieman's death as a stunt-wire yank, landing hips
first. These are drawing only: the game, its damage and demos are unchanged.
F4 → Combat → Ragdoll falls (off by default; needs Varied deaths).

Blood spray. Hits throw blood out the far side of the body and kills
burst. The drops fly as Doom-sized pixels and land as splats on floors,
walls and low ceilings. Fresh wounds drip, bodies sliding across the floor
smear it and bodies thrown into a wall splash it. A kill's wet burst and a
body slapping into the floor are heard quietly under the monster's own death
sound. F4 → Combat → Blood spray.

Knee-Deep in the Dead at night, in the rain. A new Authored episodes
switch gives id's own maps looks picked by hand rather than derived from the
WAD. DOOM's first episode now lies at night in a steady downpour, with the
sun hidden and lit rooms shining out through their windows. Maps from
Freedoom or PWADs keep the derived look, sun and all. Turn it off for the
derived look everywhere.

Rain and wear. Rain falls under the sky in streaks of whole pixels,
slanted by its own wind, and splashes or rings where it lands. Drops gather
and run down the outside of window glass, the ground under the sky lies
wet, and a few rooms beside the open sky have a leaking crack in the
ceiling dripping onto a small puddle. Through a broken window the wind
blows the rain in, and the floor and wall beneath it soak. Dark streaks run
down the outside walls below windows, rusty on metal. Plain metal plates,
such as the fronts of DOOM's computer desks, show grime in their seams,
dull blotches and boot scuffs. F4 → Weather and wear (rain: Never,
Authored episodes or Always).

Glass cracks before it breaks. The first two bullets leave small,
jagged holes with chipped edges and branching cracks. The third starts a
fracture that spreads across the pane, and pieces stay in the frame until
the cracks reach them. Projectiles and explosions still break glass
outright.

Live readouts. The blocks of glowing cells painted into computer
panels, such as the green grids beside DOOM's consoles, change now and then,
cell by cell. F4 → Glow → Live readouts.

Sounds behind the walls. Now and then, from inside the walls nearby, a
tech base works: water rushing through a pipe, steam, a duct, a press, a
drip, metal settling. It is muffled as if heard through the wall and always
comes from a wall whose texture suits it. The sounds are rare, never the
same twice running, and quiet while you fight.

The hall next door. From a corridor or small room, a bigger space
through an opening is heard as its own room. Your sounds ring faintly in it,
and sounds made inside it echo as the hall does, not as the room you stand
in.

Alternative computer sounds. F4 → Sound → Made-up sounds → Alternative
computer sounds replaces the computer bleeps with a machine hum, fine
hard-drive seeks, relay clacks and electrical chatter (off by default).

DERP, the DOOM Engine Remaster Project. Each download includes Freedoom, so you can
play straight away; add your own WADs to play DOOM, DOOM II, Heretic or custom maps.

Download

System	File	How to play
macOS 11 or newer (Apple Silicon and Intel)	DERP-mac.zip	Unzip and open Play DOOM.app. Choose your WAD folder or click Play Freedoom.
Windows 10/11, 64-bit	DERP-windows.zip	Unzip, drop your .wad files into the wads folder and run doom.exe.
Linux, x86-64	DERP-linux.tar.gz	Unpack, drop your .wad files into wads and run ./doom.

DERP-source.tar.gz is the complete source of these downloads: the
game's code plus the exact SDL and Nuked OPL3 sources it is built with, so it
builds without an internet connection. GitHub's "Source code" archives hold
the game's code only.

With no WADs in the wads folder, Freedoom starts. With a base game (such as
doom.wad or doom2.wad) and a custom map WAD, the map is loaded on top of the
game. Controls and options are in PLAY.md.

macOS: the app is not notarized by Apple, so the first launch is blocked
with "Apple could not verify…". Click Done, open System Settings → Privacy &
Security, scroll down and click Open Anyway next to the message about
Play DOOM, then confirm. After that it opens normally. (Alternatively, run
xattr -dr com.apple.quarantine "Play DOOM.app" in Terminal.)

Windows: the program is not code-signed, so SmartScreen may say "Windows
protected your PC". Click More info, then Run anyway.

Linux: you need a Vulkan driver for the 3D renderer; without one the game
falls back to the classic renderer.

Before you play

This is a pre-release. The Mac version is the most tested. The Windows and Linux
versions are built automatically but have had little real play, so please
report problems.

Supported maps: vanilla and limit-removing, including DEHACKED patches. Boom,
MBF21 and GZDoom maps are not supported. Heretic plays from your own heretic.wad
or HERETIC.WAD; Hexen is not supported yet. Multiplayer is not implemented.

DERP v0.6.0

What's new in v0.6.0

Monsters die differently every time. DOOM plays each monster's death
the same way from one angle; now the killing blow decides how it goes. Death
frames are retimed for every kill (a snap, a hesitation then a drop, a
slump), monsters killed by one rocket fall out of step on purpose, bodies
fall away from the blow and settle as they land, and now and then a hit off
the middle turns a monster or a hard push steps it back. Monsters on two
legs can also fall in ways their drawings never show, on joints placed by
hand for the zombieman, shotgun guy and chaingunner, or found in the art for
others: a low hit sweeps the legs, a hard one is a chest blast that throws
the body, and a killing head shot cuts the strings. Every hit also pushes,
so living monsters flinch and spring back. All of it is drawing only; the
game, its damage and demos are unchanged. F4 → Combat has a switch for each
piece, a Reaction strength slider, and Dying turn to face you (off by
default).

Wound holes. Bullets and pellets shoot see-through holes in monsters,
with ragged bloody edges and dark rims in the WAD's own colours. The holes
follow the animation, widen with close hits and stay on the corpse. F4 →
Wound holes.

Free aim. With mouse look, bullets now go exactly where you look, even
with a monster in front of you: aim at the head and you hit the head, aim
past and you miss. For DOOM's autoaim, turn on F4 → Classic aim (off by
default). Rockets, plasma and the BFG aim as before, and demos and netgames
keep vanilla aiming.

Windows break into real pieces. A shot pane now breaks into large,
irregular shards, smaller near the hit, with the same stepped pixel edges as
the glass left in the frame. They tumble, catch reflections while flying,
bounce and lie flat and matte on the floor. The sound was rebuilt to match: a
hard crack, then each piece catching the frame, falling, rebounding and
tipping over its edges, at 22 kHz so the bright clatter survives. A breaking
window is also heard twice as far.

Heavier footsteps. Your steps are heavy combat boots now, coloured by the
floor, harder when running and when landing from a fall. After each step
your kit settles: buckles with a light weapon, a long gun on its sling, the
rocket launcher or BFG thudding, and armour clicking when you wear it. More
floors are recognised correctly, carpet among them, and steps and room echoes
now always agree on what a floor is made of.

Sound fades as it does in air. Far sounds lose half their strength each
time the distance doubles, instead of DOOM's straight fade that keeps
monsters across the room almost as loud as nearby ones. Gunfire and
explosions carry farther, faint and dull. F4 → Sound → Natural distance
falloff (on by default; DOOM only).

Near misses whiz. An enemy's bullet from far off that passes close by
whistles past your head, so you know you're under fire.

Rooms sound like what they're made of. Rough stone and dirt scatter the
echoes and the room goes flat; smooth metal panels keep it ringing. Each echo
also loses the treble its walls take, and a texture's painted seams and
cracks make a surface sound a little rougher.

Smaller fixes. Screens stay on while the lamps in their flickering room
blink. A switched-off screen keeps its glass whole, and a shot-out lamp in a
glowing room stays dead instead of pulsing. Glowing liquid edges no longer
double up on walls that paint their own edge.

DERP, the DOOM Engine Remaster Project. Each download includes Freedoom, so you can
play straight away; add your own WADs to play DOOM, DOOM II, Heretic or custom maps.

Download

System	File	How to play
macOS 11 or newer (Apple Silicon and Intel)	DERP-mac.zip	Unzip and open Play DOOM.app. Choose your WAD folder or click Play Freedoom.
Windows 10/11, 64-bit	DERP-windows.zip	Unzip, drop your .wad files into the wads folder and run doom.exe.
Linux, x86-64	DERP-linux.tar.gz	Unpack, drop your .wad files into wads and run ./doom.

DERP-source.tar.gz is the complete source of these downloads: the
game's code plus the exact SDL and Nuked OPL3 sources it is built with, so it
builds without an internet connection. GitHub's "Source code" archives hold
the game's code only.

With no WADs in the wads folder, Freedoom starts. With a base game (such as
doom.wad or doom2.wad) and a custom map WAD, the map is loaded on top of the
game. Controls and options are in PLAY.md.

macOS: the app is not notarized by Apple, so the first launch is blocked
with "Apple could not verify…". Click Done, open System Settings → Privacy &
Security, scroll down and click Open Anyway next to the message about
Play DOOM, then confirm. After that it opens normally. (Alternatively, run
xattr -dr com.apple.quarantine "Play DOOM.app" in Terminal.)

Windows: the program is not code-signed, so SmartScreen may say "Windows
protected your PC". Click More info, then Run anyway.

Linux: you need a Vulkan driver for the 3D renderer; without one the game
falls back to the classic renderer.

Before you play

This is a pre-release. The Mac version is the most tested. The Windows and Linux
versions are built automatically but have had little real play, so please
report problems.

Supported maps: vanilla and limit-removing, including DEHACKED patches. Boom,
MBF21 and GZDoom maps are not supported. Heretic plays from your own heretic.wad
or HERETIC.WAD; Hexen is not supported yet. Multiplayer is not implemented.

DERP v0.5.0

What's new in v0.5.0

Duct-Tape DOOM is now DERP, the DOOM Engine Remaster Project. Same
project, new name, new repository address (the old one redirects). The
downloads are now DERP-mac.zip, DERP-windows.zip and DERP-linux.tar.gz.
The Mac app keeps its identity, so it still remembers your WAD folder.

Heretic. Raven's Heretic now runs on the same 3D renderer, lighting,
sound and music, worked out from the WAD like everything else. Pick a Heretic
WAD in the launcher, or put it in the wads folder, and it starts the
Heretic program that ships next to DOOM's. You need your own copy; both the
2025 heretic.wad and the original DOS HERETIC.WAD work. The effects are
tuned for its world: torches, chandeliers and serpent statues light their
rooms, stained glass glints and throws its colours on the floor, water is a
clear mirror, the Ice Grotto's floor is glassy, and the Torch item is a
flickering flame you carry instead of a flashlight. There is no window glass
and nothing to shoot out, and Heretic's own wind and waterfall sounds play
instead of DERP's made-up ones. Heretic is new and far less played than
DOOM; see heretic/README.md for what works and what doesn't yet.

Embers. Torches and fires shed a few one-pixel sparks that rise and cool
to dark red; in Heretic the game's wind carries them off. F4 → Embers.

Glowing liquid edges. Walls running straight into nukage, slime or lava
take the glowing strip the game paints on its own edge textures, like the
NUKE24 steps, instead of only the walls a mapper gave that texture.

Shore ripples. Liquids ripple along the walls they meet, drawn like the
splash rings: quick thin lines on water, slow broad ones on nukage and
slime, slow glowing ones on lava, a still dark line on blood.

Big pools look like one body of liquid. Far away and at grazing angles a
liquid's detail fades toward the animation's average colour, and the surface
drifts between calmer and rougher patches with long wave bands in the
reflection, so large pools stop reading as a tiled flat.

DERP, the DOOM Engine Remaster Project. Each download includes Freedoom, so you can
play straight away; add your own WADs to play DOOM, DOOM II, Heretic or custom maps.

Download

System	File	How to play
macOS 11 or newer (Apple Silicon and Intel)	DERP-mac.zip	Unzip and open Play DOOM.app. Choose your WAD folder or click Play Freedoom.
Windows 10/11, 64-bit	DERP-windows.zip	Unzip, drop your .wad files into the wads folder and run doom.exe.
Linux, x86-64	DERP-linux.tar.gz	Unpack, drop your .wad files into wads and run ./doom.

DERP-source.tar.gz is the complete source of these downloads: the
game's code plus the exact SDL and Nuked OPL3 sources it is built with, so it
builds without an internet connection. GitHub's "Source code" archives hold
the game's code only.

With no WADs in the wads folder, Freedoom starts. With a base game (such as
doom.wad or doom2.wad) and a custom map WAD, the map is loaded on top of the
game. Controls and options are in PLAY.md.

macOS: the app is not notarized by Apple, so the first launch is blocked
with "Apple could not verify…". Click Done, open System Settings → Privacy &
Security, scroll down and click Open Anyway next to the message about
Play DOOM, then confirm. After that it opens normally. (Alternatively, run
xattr -dr com.apple.quarantine "Play DOOM.app" in Terminal.)

Windows: the program is not code-signed, so SmartScreen may say "Windows
protected your PC". Click More info, then Run anyway.

Linux: you need a Vulkan driver for the 3D renderer; without one the game
falls back to the classic renderer.

Before you play

This is a pre-release. The Mac version is the most tested. The Windows and Linux
versions are built automatically but have had little real play, so please
report problems.

Supported maps: vanilla and limit-removing, including DEHACKED patches. Boom,
MBF21 and GZDoom maps are not supported. Heretic plays from your own heretic.wad
or HERETIC.WAD; Hexen is not supported yet. Multiplayer is not implemented.