Using cheat and console commands can potentially break your game and quest chains so use them responsibly or it will ruin your gaming experience

Sometimes it is better to reload than cheat your way out of a situation

In Gothic 3 Forsaken Gods Enhanced Edition that comes with inbuilt Community Patch Cheat mode seems to be enabled by default.

All you have to do is quickly type marvin on your keyboard and a message saying that Marvin Mode has been enabled will pop on screen.

In order to access console press ` tilde key which is to the left of number one key, under ESC.

You can also use various keyboard button shortcuts to use certain cheats.

Cheats are basically same as in Gothic 3. If you are used to Marvin mode in previous Gothic installments like Gothic 2 you will find it similar in many ways, except that most keyboard shortcuts not require you to hold CTRL while executing them.

In my opinion Marvin mode in G3 is more annoying than in G2. And it is not really needed, except maybe in a rare occasion you get stuck and your last save is way back when. In this case you need to use CTRL + K shortcut to teleport forwards. You can hold it and it will allow you to cross the map at an insane speed. It works like Noclip and speedrun at the same time.

K and F8 are useful commands in G2 in my opinion because of how long it takes to get to places, so you can just use them to get to places faster. But in G3 you already have sprint so you don't need to use those things to save time. Luckily some total conversion mods even add sprint into G2 based on Speed Potion effect so you don't always need those, like Returning 2.0 with Stamina stat or Odyssee 2.0 with jewelry effects.

There is also no Systempack hack No_Take_Anim=0 to skip the slow pickup animation in G3 so in order to pick things fast you just need to crouch by holding CTRL and spam left click to pick everything up really quickly

There is also character helper but he now only deals with story. He can fast forward story to certain points for you. Open console and type insert sh

p.s. if for any reason Marvin mode does not start and you are sure you have typed it fast and correctly try doing this: open the ge3.ini file located in Gothic 3 Forsake Gods/Ini folder and change the following line : TestMode=false to TestMode=true. Cheats should work after that.

Default path to the installation is C:\Program Files (x86)\Steam\steamapps\common\Gothic 3 Forsaken Gods. You can always right click the game in your Steam Library, select Properties, Local Files and Browse to get there without searching.

Commands are in bold, description is in regular

Console commands that you type in:
God - Invincibility
Teach all - Learn every skill
Help - Show command list
fullhealth - regain health
Kill - Kills your target
Give [item_name] - Get a specific item
Spawn [item_name] - Create a specific item or NPC
give It_Gold [amount] - Get an amount of gold
idkfa - Give all
give Cat_Armor - Give all armors
give Cat_Weapon - Give all Weapons
give Cat_Artefact - Give all jewelry and such
control - Take over an NPC
watch - Change camera
teach attributename will set an attribute of your choosing to a specific height i.e. teach STR 90

Attributes for teach command:
STR - Strength
DEX - Hunting Skill
INT - Ancient Knowledge
ALC - Alchemy
SMT - Smithing
THF - Thieving
HP - Health Points
MP - Mana Points
SP - Endurance/Stamina Points

teach LP - Will award you with a number of unspent skill points that you can use at a trainer or a god statue i.e. teach LP 100

Key combination commands:
F8 - Revive/Reset Player
CTRL+K - Teleport noclip forwards, if you hold it it becomes a speedrun, fly, swim cheat

After enabling Marvin mode by typing marvin fast press the following keys or key combinations on your keyboard for them to take effect. The key commands are in bold, the regular non bold letters explain their effects.

F6 Accelerate/brakes the play time
F7 OnPlayerToggleSloMo
NUM 7 OnIncEnclaveTheftCount
NUM 8 OnIncEnclaveMurderCount
NUM 9 OnIncPoliticalCrimeCount
F12 Quit Application
LEFT CTRL+S Toggle Global Stats
LEFT CTRL+M Toggle Memory Statistics
RIGHT CTRL+M Memory Statistics Snapshot
F1 Make Snapshot
F2 Toggle Fullscreen
F3 Toggle RenderMode
LEFT CTRL+NUM 1 Toggle AvS Solid
LEFT CTRL+NUM 2 Toggle AvS Object Overdraw
LEFT CTRL+NUM 3 Toggle AvS Pixel Overdraw
LEFT CTRL+NUM 4 Toggle Performance Solid
LEFT CTRL+NUM 5 Toggle Performance Object Overdraw
LEFT CTRL+NUM 6 Toggle Performance Pixel Overdraw
LEFT CTRL+O Toggle Object Overdraw
LEFT CTRL+P Toggle Pixel Overdraw
LEFT CTRL+C Toggle Color Mapping
LEFT CTRL+U Toggle Solid Plus Wireframe
LEFT CTRL+G View Gamekeys
LEFT CTRL+R Toggle Rays
LEFT CTRL+RETURN Start Game
LEFT CTRL+BACKSPACE Stop Game
LEFT CTRL+F4 Pause Game
LEFT CTRL+Q Collision Shapes
LEFT CTRL+F Control Focus
LEFT CTRL+W Watch Focus
LEFT CTRL+SPACE Toggle Editor
F8 Reset (Revive) Player
LEFT CTRL+V Toggle Vegetation
LEFT CTRL+E Cycle Postprocessing
LEFT CTRL+I Cycle Lightningmodes
LEFT CTRL+L Cycle Moving Light
SHIFT+S Toggle SpeedTree
LEFT CTRL+B Toggle Bounding Boxes
LEFT CTRL+PAGE UP Goto Camera
LEFT CTRL+INSERT Free Camera
LEFT CTRL+HOME Fixed Camera
LEFT CTRL+K Teleport Player Forward, (Noclip+Speedrun) Hold for continuous effect
LEFT CTRL+SCROLL Single Step
LEFT CTRL+H Goto Startposition
LEFT CTRL+A Toggle AI Debug
LEFT CTRL+R Profile All
LEFT CTRL+N View Navigation
LEFT CTRL+N+P Pause Navigation
LEFT CTRL+N+M Reset Navigation
LEFT CTRL+H+CURSOR LEFT Move Start Nav Point Left
LEFT CTRL+H+CURSOR RIGHT Move Start Nav Point Right
LEFT CTRL+H+CURSOR UP Move Start Nav Point Up
LEFT CTRL+H+CURSOR DOWN Move Start Nav Point Down
LEFT CTRL+J+CURSOR LEFT Move Goal Nav Point Left
LEFT CTRL+J+CURSOR RIGHT Move Goal Nav Point Right
LEFT CTRL+J+CURSOR UP Move Goal Nav Point Up
LEFT CTRL+J+CURSOR DOWN Move Goal Nav Point Down
LEFT CTRL+0 Walk Animation Mixing

Like above, Console commands are in bold now.

god Invincible mode. Infinite mana and health
fullhealth Refills health
idkfa Player gets all items/skills in the game
defeat something you should not use!
audio.fAmbientVolume sets the ambient volume
audio.fEffectVolume sets the effect volume
audio.fMasterVolume sets the master volume
audio.fMusicVolume sets the music volume
audio.fVoiceVolume sets the voice volume
camera.fAziSpeedScale scales the azimuth angle velocity around target (default: 1.0f)
camera.fElevSpeedScale scales the elevation angle velocity around target (default: 1.0f)
camera.fFieldOfView toggles the camera's field of view (default:90)
camera.fMaxDistToPlayer sets the maximum clamped distance to the player
camera.fMoveSpeed sets the movement speed of the free camera (default: 300.0f)
camera.fMoveSpeedAccel sets the movement speed modificator if pressed [SHIFT] (default: 3.0f)
camera.fMoveSpeedDeccel sets the movement speed modificator if pressed [CTRL] (default: 0.5f)
camera.fRelaxCamera sets the camera pos relax factor
camera.fRelaxDist sets the camera dist relax factor
camera.fRelaxFOV sets the camera fov relax factor
camera.fRelaxPlayer sets the player pos relax factor
camera.fRelaxXAxis sets the camera x axis relax factor
camera.fRelaxYAxis sets the camera y axis relax factor
camera.SetMode sets the current camera mode
camera.ShowPosition shows the current position of the camera
camera.ToggleModeChange enables or disables the mode changes of the camera
caps.DisableAlphaRendering
caps.DisableModuleRendering
caps.DisableStencilTesting
caps.EnableDynamicVisualsRendering
caps.EnableLightMaps
caps.EnableObjectVPTHCCulling
caps.EnableOcclusionCulling
caps.EnableStaticVisualsRendering
caps.EntityProcessingRangeSphere changes the EnterProcessing range, must be greater than the processing range
caps.EntityROI changes the processing range, must be smaller than the EnterProcessingRange
caps.FarClippingPlane changes far clipping plane
caps.FarClippingPlaneLowPoly changes far clipping plane for lowpoly mesh
caps.GlobalVisualLoDFactor Global property for visual mesh lodding: 1.0f = default value > 1.0 use only for high end systems, < 1.0 for slower machines
caps.OCCheckThreshold
caps.OCPixelOverdrawThreshold
caps.RenderDebug toggles rendering of entity debug infos
caps.ScreenObjectDistanceCulling Simple distance screen metric object distance culling used. Culls all objects under threshold
compile navigation (re-)compiles the navigation scene!
console.font defines the font of the output window
console.dimy defines the y height of the console in pixel (default 250)
console.dimx defines the x width of the console in pixel (default: renderer width)
console.posy defines the y pos of the console in pixel (default 0)
console.posx defines the x pos of the console in pixel (default:0)
console.filterlevel defines the spy filter level (default 5)
console.outputlines defines the number of buffered output lines in the console (default: 5000)
colorscheme choose next color scheme
control controls the given entity or the focus/editor entity if no name given (assigned to key: LEFT CTRL+F)
DebugShowDiffMem shows memory diff output in zspy and traceview
DebugShowMem shows memory output in zspy and traceview
DisablePrefetcher Disables prefetcher
dispose disposes items from the inventory
dViewGameKeys() Prints all active gamekeys and debug-actions on screen (assigned to key: LEFT CTRL+G)
edit edits the current entity
EnablePrefetcher Enable prefetcher
focus.ShowTA() toggles the focus ai debug mode (assigned to key: LEFT CTRL+A)
game.bTestMode toggles the testmode on or off, 0: off, 1: on (default:1)
game.Chat() start an irc chat session
game.ForceCrash guess what!
game.ForceFloatException causes a floating point exception!
game.SetTime Sets the World Time liket ..SetTime 12
game.ShowVersion prints out the current game version
game.WatchFPS opens a statistic control with fps output
give places an instance of the given item in the player's inventory
goto beams player and camera to the given entity
gotocamera beams player to camera position (assigned to key: LEFT CTRL+PAGE UP)
illumination.CycleLightningModes cycles through all lightning modes (assigned to key: LEFT CTRL+I)
illumination.CycleMovingLight cycles through all moving light modes (assigned to key: LEFT CTRL+L)
illumination.SetPixelHemispherePixelLightning set the lightning to pixel hemisphere mode
illumination.SetSimpleLightning set the lightning to simple mode
illumination.SetVertexHemispherePixelLightning set the lightning to vertex hemisphere mode
illumination.SetVertexHemisphereVertexLightning set the lightning to vertex hemisphere mode
invisibility something you should not use! Makes all enemies not react to you
kill something you should not use because you can kill essential characters that way Kills targeted enemy
music.bEnableAutoUpdate enables or disables automatic updates
music.bEnableTriggers enables or disables accepting triggers
music.sDayTime sets the daytime
music.sLocation sets the location
music.sSituation sets the situation
PhysicFPS steps the physicscene at [n] fps
physics.dToggleActorAxes Toggles the visualization of the axes of the physic actors
physics.dToggleBodyAxes Toggles the visualization of the axes of the bodies of the physic actors
physics.dToggleContactForce Toggles the visualization of the contact forces acting on the bodies of the physic actors
play ani syntax: play ani [a1] [a2] [ib] [name] plays the ani [a1] to [a2] with optional blending [ib]
player.fForwardSpeedMax sets the maximum forward speed of the player in m/sec (default: 300.0)
player.GotoStartPosition() beams the player to the starting point (assigned to key: LEFT CTRL+H)
spawn spawns an instance of the given entity name
trigger triggers the given entity or the focus/editor entity if no name given
version prints the engine version
quit closes the application's window
history prints the history of entered commands
help prints a help line for each command
clear clears the console output
physics.dToggleBodyMassAxes Toggles the visualization of the mass-axes of the bodies of the physic actors
physics.dToggleRays Shows ray debug lines (assigned to key: LEFT CTRL+R)
physics.dToggleStatistics Shows some physics debug output
Remotedebugger starts a remote debugging session on the target machine [localhost], if nothing entered
show position display the current camera position
spy.AddComment adds a comment line in the spy
stats.dToggleGlobal() Toggles global scene-debug-output (assigned to key: LEFT CTRL+S)
teach teaches the specified spell(s) and/or skill(s)
timer.fTimeScale sets the time scale value (default: 1.0)
toggle memdebug tests the memory for corruptions (SLOW!)
untrigger untriggers the given entity or the focus/editor entity if no name given
view.dShowLabels() visualizes all relevant label psets
view.dShowLights() visualizes all relevant light psets
view.dShowNavigation() visualizes all relevant navigation psets (assigned to key: LEFT CTRL+N)
watch controls the given entity or the focus/editor entity if no name given (assigned to key: LEFT CTRL+W)
world.ToggleFolder enables or disables the given sector-folder
world.ToggleSector enables or disables the given sector

Thank you for reading and I hope you enjoy the game!