Good question
all drawbacks

Here is a list of all drawback that I discovered:
Rook Buddies
You can’t move your rooks until you connected them
Skittish
While in check, you must move your king
Untitled duck drawback
There is a duck sleeping on (random square). You can’t pass through it or land on it
Greedy
You can’t capture a piece if you could have captured a higher-value piece
Separation Anxiety
Your pawns that are adjacent to your king cannot make moves that leave the squares adjacent to him (your king can leave them behind)
Crossing the Rubicon
Once one of your pieces crosses onto your opponent’s side of the board, it can’t return back to you
Queen Disguise
Your queen is secretly either a rook or a bishop. Once you move like one, you can’t move it like the other
Queen Bee
Once you capture with a queen, you can no longer move queens
Entrenched
Your rooks can’t move more than 2 squares
Cess
You can’t move to the h file
Out of Breath
You can only move your king once
Shadow Queen
Your queen can only move to dark squares
Horse tranquilizer
Your knights can’t capture
Quit horsing around
If you moved a knight on your last move, you can’t move a knight
Royal Jubilee
Whenever you capture a non-pawn piece, you must move your king or queen on the next move
Three Check
If you are checked three times, you lose
Number of the Beast
You can’t move to the sixth rank
Prima Donna
You can’t have more than one pawn on the same file
Separation of Church and State
You can’t move your bishops next to a king and you can’t move your king next to a bishop
Escort Mission
If your king can capture, it must
Champing at the Bit
Your pawn moves must all be distance 2
Battle Fatigue
When one of your pieces captures, it can’t capture again until it has made a non-capturing move
No shuffling
Your rooks can’t move sideways
Outflanked
Except for capturing king, you can’t capture on the rim
Professional Courtesy
You can’t capture non-pawn pieces with pieces of the same type (e. g. your knights can’t capture knights)
Snipers
Your bishops can only capture from a distance of at least 8 (4 diagonal squares)
Diplomatic Immunity
You can’t capture a piece that just moved unless that move was a capture
Simplifier
If you can capture a piece with a piece of lesser or equal value, you must
Sleepy King
Your king can only move when in check
Femme Fatale
You can only capture their king with a queen
Get Down Mr. President
You can’t move your king when in check
Power Cells
You can’t move a piece farther than the number of pawns you have
Unspooling
You can only move a total of 100 distance. Once you run out, you lose
Evil Twin
If you can capture a piece with spa a piece of the same type, e.g. capture a knight with a knight, you must
Doctor Octopus
You can only capture non king pieces 8 times
Protected Pawns
Can only move pawns to defended squares
Just Passing Through
You can’t capture on the (random number) rank
Stay at Home Mom
Your queen can only make moves to your two home ranks
Remorseful
You can’t capture twice in a row
Siege
You must take at least one of your opponent’s rooks by move 20 or you lose
Shapeshifter
Your queen starts out as a bishop. Whenever you capture a non-pawn piece, your queen becomes a copy of it. If you capture a knight, your queen becomes confused and doesn’t know what to do, so can’t move
Conscientious Objectors
Can’t capture with pawns
Respectful
You can’t give check
Trophy Wife
Your queen can’t capture
Horse Eats First
As long as you have a knight, you can only capture with knights
Punching Down
Your pieces can’t capture pieces worth more than them (anything can capture a king)
Elephants Fear Mice
Your non-pawn pieces can’t capture pawns
Windup Toys
After the first 12 moves of the game, you can’t move your knights and bishops
Abstinence
If your opponent ever has two non pawn pieces of the same type adjacent to each other, you lose
Simp
Lose if you have no queen
You Best Not Miss
If you end your turn checking your opponent, you must capture their king on the next move (or lose)
Ivory Tower
You lose if there’s an opposing piece adjacent to your king
Eye of Sauron
As long as you have a rook, your non-pawn pieces can’t move to a rank more advanced than the farthest square your rooks can see (a square they’re on or can move to)
Hipster
Can’t move the same piece type as your opponent’s last move
Savior Complex
When in check, you must move your queen (or lose)
Reconnaissance
You start being enable to capture. Every turn, you study all the pieces you would be able to capture normally, and once you studied them for a turn, you can capture that piece type for the rest of the game
Control Center
Your non-capturing moves must be to the four central files
Haunted
You can’t move to a square that you have captured on
Tower Defense
You can’t move your rooks. If you lose all your rooks, you lose
Paranoid
Your king must always be defended (you must be able to recapture if it were captured, or you lose)
Bipartisanship
You cannot move left twice in a row or right twice in a row
Shellshocked
Whenever your opponent captures, pieces adjacent to the capture can’t move for one turn
Comfort Zone
If you can move to (random square), you must
True Gentleman
Can’t capture queens
King of the Hill
Except for the first turn, if you start your turn without a piece in the center 4 squares, you lose
Lethal Attraction
You can’t make moves that place the moving piece farther away from your opponent’s king than it started
Modest
You lose if you have more pieces than your opponent
Triple Play
You can only capture their king if you have three (random piece)
Sibling Rivalry
You cannot move a piece to a square adjacent to an opponent’s piece of the same type
Torchlight
Your non-pawn pieces can only make moves that start or stop adjacent to to one of your pawns
Vegan
You can’t capture knights
Turn the Other Cheek
You cannot recapture
Gambler
Can’t move a specific piece type, re-randomized every move
Blinded by the Sun
You can’t end your turn attacking (random square)
Bishop Fan Club
You must promote to bishops. Your king and queen can only move diagonally
Truant
You can’t move the same piece twice in a row
Chivalry
You can only capture their heavies (rooks and queens) with a knight
Lame Duck
You can’t move your king
Spread Out
You can’t move a non-pawn piece adjacent to another one of your non-pawn pieces, and you can’t castle
Stop Stalling
Your pieces can’t move laterally
Peons First
Can’t move pieces that are one square behind one of your pawns
Moving Day
At the start of move 21 and onwards, your pieces can’t be on your home row
Oddball
You can only capture on odd-numbered moves
Even Keeled
You can only capture on even-numbered moves
Social Distancing
You cannot make non-capturing moves to squares adjacent to your opponents pieces
Far Sighted
Your pieces can’t capture pieces that are adjacent to them
Hold them Back
You lose if your opponent moves a pawn to your side of the board
Whites of Their Eyes
Your capturing move must be of distance 2 or less
Drag
Your queen is a king. It moves like one, and if it’s captured, you lose
Stir Crazy
If you haven’t moved your king 4 turns in a row, you must move it on the fifth
Rook on the Seventh
By move 15, you must move your rook to the seventh rank
Guerilla Tactics
After playing à capturing move, you must return the capturing piece to its previous location if possible
Cheerleaders
Your non-pawn pieces can only capture if they’re adjacent to one of your pawns
Scouting Ahead
As long as you have a pawn, you cannot move non-pawn pieces ahead of your most advanced pawn
Spice of Life
You can’t move the same piece type twice in a row
Warlord
At the start of move 12 and onwards, your king must not be on the first two ranks (or you lose)
Medusa
Any pieces that are currently attacked by your opponent’s queen are turned to stone and can’t move
Fischer Random
On or before move 20, all your remaining non-pawn pieces must be on your home row, on a square that it could not have started on (e.g. rooks may not be on the A or H file)
Centralized Command
You can only capture if you moved your king in the last three turns
Stand Your Ground
Your pieces can only capture if they are attacked
Always Check, It Might Be Mate
If you are checked, you lose
Glorious battle
For four consecutive moves, starting on move (random number), you must capture (or lose)
Flatterer
If your opponent moves a pawn, you must move a pawn. If your opponent moves a non-pawn piece, you must move a non-pawn piece
Messy Divorce
Your pieces can’t move from the queenside to the kingside or vice versa
Leveling up
You can’t capture a piece until you captured its predecessor in the list [pawn, knight, bishop, rook, queen, king]
Homeland Security
If your opponent moves into your 16 starting squares, you lose
Cowering in Fear
You can’t move a piece of less value than one your opponent has taken
Barbarian Rage
If you captured on your last move, you must capture if able
My Kingdom for a Horse
If your opponent captures a knight, you lose
Ey for an Eye
If your opponent captures, you must capture on your next move, (or lose)
Simon Says
You must move onto the same color square as your opponent last move
Irresistible
If you can move a piece adjacent to your opponent’s king that isn’t already, you must, except that you are always permitted to capture their king
Boastful
You lose if you have fewer pieces than your opponent
Winds of Fate
Every turn, you will be randomly be unable to move either left or right
Monkey See
You can only capture with piece types that your opponent has captured with
True Love
Your king can only make move that place it adjacent to your queen (and can’t move if you don’t have a queen). Your queen can only make moves that place it adjacent to your king
Superstitious
You can’t move to a square that your opponent has captured on
Rising Water
Every 10 turns, the water level rises one rank. You can’t move pieces that are underwater and you can’t move to squares that are underwater
Eat Your Vegetables
You can’t capture non-pawns until your opponent only has 4 pawns remaining
Bloodthirsty
After the first 3 rounds, if you go 2 turns without capturing, you must capture on the third (or lose)
Left for Dead
You can only capture to the left
Pacman
If you can capture a pawn, you must
Crusade
For four consecutive moves, starting on move (random number), you must end your turn occupying (random square)
Pack Mentality
Your pieces must move to squares adjacent to another one of your pieces
Scorched Earth
You can’t move to a square that you’ e moved from
Fog of War
You can’t see your opponent’s pieces (you can still see when a possible move is a capture or a king capture, though, and you know when you’re in check)
Hedonic Treadmill
You must move a piece at least as valuable as your opponent’s last moved piece
Death Wish
If you can move your king into check (and aren’t already in check), you must
Checkers
You must capture if able
Closed Book
You lose if you ever start your turn while there’s an open file (one with no pawns)
Fixation
Once you move a particular pawn, you cannot move a different pawn until you move a non-pawn piece. Once you move a particular non-pawn piece, you cannot move a different non-pawn piece until you move a pawn
Covering Fire
You can only capture a piece if you can capture it two different ways
Unlucky
Can’t move to half of squares, re-randomized every move
Jumpy
When possible, you must move a piece that is being attacked
Hopscotch
You must alternate moving to light and dark squares
Leaps and Bounds
You can’t move a piece adjacent to where it was
Colorblind
Can’t move to squares of one color, re-randomized every move
Inching Forward
After move 6, your king must be in front of your home rank. Every six moves after, the rank it must be moves forward by one
Ichtyophobe
You can’t make the move that stockfish would make
Left to Right
Unless you just moved to the rightmost file, you must move to a file to the right of where you last moved
Friendly Fire
Can only move to squares defended by your other pieces
Going the Distance
You must move at least as far as your opponents last move (or lose)
Helicopter Parent
You lose if you have an undefended pawn
Exclusivity Clause
You can’t move to squares that more than one of your pieces can move to
Relay Race
If you can move a piece that’s adjacent to the destination of your last move, you must
Devil on Your Shoulder
A devil is suggesting terrible moves for you to make. If you disobey it 7 turns in a row, you must obey in the 8th
Reflective
You can only move non-pawns to squares whose opposition square reflected across the center line is occupied
Alternator
You must alternate pawn moves and non-pawn moves
Cowardly
When your opponent captures, you must move backward (or lose)
Obsession
Every turn, pick a random square. If you can move to it, you must
Boxing with Shadow
When your opponent moves a piece, if you can move to the square they moved from, you must
Noble Steed
Your non-Knight pieces can only move if they’re adjacent to one of your knights
Deer in the Headlights
You can’t move pieces under attack
Hand and Brainless
Must move a specific piece type, re-randomized every move
Hope that this list helped you

I played a little more and discovered more drawbacks
yea lets keep updating things here.

Here is an little update
Hand and Gigabrain
You must move the piece type that Stockfish recommends
Lucky
No drawback
Crenellations
Your pawns can only move to (random color) square
The Scent of Blood
You can’t make non-capturing move with a piece that can capture
Leading the Charge
As long as you have a knight, you cannot move non-knights ahead of you’re most advanced knight
Active Volcano
You can’t move onto or orthogonally adjacent to (random square)
Nurturer
You can’t capture their king until you promoted a pawn
Prince Charming
If your queen is attacked, you must move a knight if possible
Absolution
When one of your non-bishop pieces captures, it must seek absolution by starting its turn adjacent to one of your bishops before it can capture again
Quicksand
The middle two ranks are quicksands. If one of your pieces ends the turn on the same square in the middle two ranks twice in a row, it can never move again
Rook Fan Club
You must promote to rooks. Your king and queen cannot move diagonally
Ladies First
You can only move your king if you moved your queen on the previous move
Inside the Lines
You can’t move onto the ring (you can make move moves that start and stop on the rim)
Bridge Over Troubled Water
There is a river in the middle of the board. You can’t land on it and you can only pass over it via the bridge in the center two files
Royal Berth
You can’t make moves that place a piece adjacent to your king
Velociraptor
You can only capture a piece if your opponent has moved a piece of that type in their last three moves
Secret Garden
You have a secret garden in front of (two of) your pawns. You can’t move onto it, and if your opponent tramples it (moves onto it), you lose
Forward March
Can’t move backwards
Thunderdome
The middle 16 squares are the thunderdome. Once one of your pieces enters the thunderdome, it can’t leave unless it’s the only piece in the thunderdome
Indecisive
Your pieces can’t capture if they could make multiple capturing moves
Unrequited Love
Your king can’t make move away from your queen (and can’t move if you don’t have one). Your queen can’t make move towards your king
Torpedos
If you made a non-capturing move with a pawn on your previous turn and you can move it again this turn, you must
Theocracy
On (odd or even)-numbered moves, you can only capture with your bishops
Bottled Lighting
If you can move your king, you must

I prefer only the very easiest to low medium drawbacks because im using the restrictions for training purposes. The harder ones are pretty unrealistic to apply lol
ive become interested in drawback and although the concept of slowly uncovering all them may be fun to some Id like to just know what all the drawbacks are from easiest to hardest. Does anyone know ?