Fixed

Enchanting:

Base:

Items have an “enchant capacity” based on what item it is (roughly 43% of how many enchants they item has in total i.e. boots>chest plate) capped at 50 levels
Enchants have an “xp cost” which increases exponentially based on its level, that enchants max level and if it is treasure. Max level of enchants 8-12 (10 average) xp levels
Loot has a chance to have an enchant that is over the normal limit (super enchants, has green glint)

Enchanting table:

Can not enchant books
Starts by giving 1 low level enchant
Adding bookshelves makes enchant chance to be higher level
For every bookshelf, it will check a random position with the table range, if chiseled bookshelf, checks random slot, if enchanted book, gets all the “valid” enchants on it (can apply to type of item, not already applied/current level is lower than book, not silk-fort incompatible) and chooses one at random.
Required xp levels is the total cost of all the enchants on the item (mininum 1 level)
Lapis/Xp cost is required levels divided by 10 rounded up i.e. 42 is 5
Icon of output show if item will be under half/over half or over capacity (The 3 buttons rather than being low medium high are 3 random selections

Anvil:

Can not combine enchants from different tools
Xp cost is sum total of all enchants on final output regardless of input items (1 if <= 0)
Display how of the capacity is used up on output item via a bar, notches every 5 levels
Cant deal with items over the xp capacity or contain a super enchant (bar shows red)

Netherite anvil:

Crafted with anvil, netherite block and upgrade template in smithing table
The more expensive the item used, higher chance of anvil damaging (5% + levels over capactiy + 10% if super. 0% if under capacity)
Does not care about the capacity of the item or if it has a super enchant
Output can not have mending

Other:

Most mutual restrictions gone (apart from some like silk-fortune)
Gold items half the XP cost, and when enchanted via table, where possible, each enchant gains a level (even becoming super enchants), additionally have unlimited capacity. (Tools have stone durability, and can break the same as iron tools)
Curses have negative XP cost
Netherite gear only requires scrap to repair, tridents can be repaired with prismarine shards
Ingame GUI to show what book you are looking at in a chiseled bookshelf
Bottle O’ Enchanting can be crafted via sculk blocks
XP dropped on death equates to half the levels you had on you
Taking enchants off an item via grindstone costs one materials worth (to limit endless enchanting attempts)
Alternative protections don’t adhere to the 80% cap, but normal protection no longer gives points to them
Bane of Arthropods has also been renamed to Bane of Invertebrates as it now also affects creepers, slimes, magma cubes, guardians, shulkers, ghasts, vexes, blazes (and breezes in 1.21)
Thorns does less damage and less durability but stacks with other pieces of armour
Riptide is buffed and can be activated by standing in a lingering water cloud

Transportation:

Stamina:

Saturation value refitted into a stamina mechanic, displayed over your hunger
Performing actions such as sprinting and jumping will drain your stamina, the better the armour, the quicker it drains
Standing still/walking turns hunger into stamina, sneaking increases speed but costs more hunger or heals if standing still
Running out of stamina stops you from sprinting, full stamina heals you
Foors give both hunger and stamina, the more hunger it gives, the longer it takes to eat. Golden foods take the longest
Bowl foods stack to 16, Glistering Melons are now edible and heal a heart upon consumption and Glow Berries give you a temporary glowing effect
The new Echo Fruit teleports you back to your last death location

Horses:

Saddles are now craftable
Horses can now move through leaves (at slower speed) and get into a boat
Horses trot by default and trying to sprint gets them to gallop
Using an ender pearl on a horse teleports the horse too
Horse Armour now enchantable with boot enchants (minus unbreaking/mending)
The better the armour the less chance the horse has of buckling which reaches 0 with netherite horse armour
When breeding a horse, the parents will take the potion effect they have with the longest duration of regen, swiftness or leaping in order to give a slight buff to the babies health, speed or jump height
Mules have less chest space than a donkey, but can now wear horse armour
Zombie horses have a chance to spawn in zombie sieges, riding one will make mobs less likely to see the player

Minecarts:

Added copper rails which allow minecarts to have a higher max speed based on the oxidisation, but they require an external energy source
Buffed Furnace Minecarts to reach new max speeds
Cancelled further Development due to issues with high speeds and news of minecart experimental features

Elytra:

The elytra now takes 3 quarters of a second of air time or riptide to activate, but you can just hold space and it will automatically deploy when it can
Taking damage disabled the elytra for 2 seconds or touching the ground
Does not work when the playing is touching water, rain or lava
Normal fireworks no longer boost the elytra but must be converted into dragon fireworks using dragon’s breath or add a star into them causing an explosion when used

Mapbook:

Combine your maps together into one cohesive map book
Shows closest map to location when held, stiches all maps together in gui when clicked
Can add more maps by having paper in inventory when in uncharted areas, or with a filled map in offhand or crafting table
Can be cloned with another book in crafting table
Can add banners like normal maps by clicking them, also adds treasure map icons
Players with same mapbook id in their inventory can show their location from anywhere
Shows x and z coords of mouse (middle click teleports to them if player has permissions)
Allows Curse of Vanishing to prevent other players stealing it

Boats:

Packed and blue ice melt in the nether (Gamerule default true)
Mobs will now leave boats when attacked

Inventory:

The bundle can hold up 64 normal items, 32 throwables or 4 unstackables
2x2 crafting grid stores items like the rest of the inventory
Items dropped on death on normal last 10 minutes and don’t despawn on easy
Llamas now spawn in all Savannah biomes, and their strength value has a better formula to determine how much bred llamas can hold, and they teleport back to the caravan if they get lost

Combat:

Snapshots:

Loyalty Tridents return from the void, imapling works on all mobs touching water
Getting hit while eating resets the animation
Potions stack to 16
Different weapons have different attack ranges and you can hit mobs through grass
Shields have no delay, but use up stamina when held up

Totems:

Totems now turn into a broken form upon use requiring a nether star to be fixed
New echo totem teleports you to your respawn point upon use
Require holding up a totem for it to work (Gamerule default false)
2 thirds of the evokers in raids are replaced with illusioners who now cast a 15 second nausea spell when entering combat and shoot 4 second blindness arrows, and drop these new blindness arrows upon death

Other stuff

Can throw bricks, and can be shot out of dispensers (also tridents)
Goat horn directs pet wolves to attack
Hostile mobs spawned under the night sky will drop more XP on death, and those that spawn underground have a chance to spawn with a potion effect
The armour and weapons on mobs have become more randomised, including coming pre-trimmed, and their health and speed have a chance to be increased based on the difficulty
Zombie villagers will only spawn on the surface, endermen more common in deserts, cave spiders under mountains

Phantoms:

Phantoms have a smoother swoop and don’t turn towards the player when travelling at high speeds
Phantoms deal no knockback
Don't spawn when player is near a cat
Dive into the ground and despawn in the morning
Spawn if player has insomnia effect which is given to the player if they haven't slept for 3 nights
Killing phantoms increases level which spawns more phantoms
Sleeping with insomnia turns its level into a health boost (5 min and 2 hears per level)
Can eat membrane to force give insomnia as well as a short blindness debuff

Wither:

The wither now moves slower towards the player and circles around them when close enough
At half health they will cause an explosion and spawn 3 wither skeletons as the wither now will speed up and now phase through blocks as it comes down to the players level
The wither can not be heal back into its first phase

Dragon

Upon entering the end, you will see 4 end crystals around the exit portal which begin to summon the dragon when approached
Real Boss music
The Ender Dragon will shoot fireballs more commonly that have explosion damage and don't hit the dragon herself
Will now occasionally charge at the player causing high knockback
Sometimes will drop an endermite out of the sky, if not killed quickly, nearby enderman will attack it then turn and aggro onto the player
When perched, the dragon will face towards the player and so not let the player under her anymore, and if the player is too far away, the dragon will shoot a fireball.
Will activally chase players flying with an elytra
Can hit the dragon with spectral arrows
There will be a world border around the island until the dragon has been defeated for the first time,
Respawned dragons can’t break blocks unless you
summon the dragon while having bad omen which will make the fight harder as the dragon will more faster, deal more damage and have other modifications such as setting you on fire when breathed upon, but you collect double the dragons breath, get 3 times the xp on kill and an additional elytra and dragons egg as a reward for winning

Other

Villagers:

Villagers will now increase their prices if they have not gossiped with at least 2 other villagers or slept recently
Do not sleep if they see more than one other villager
Enchanted books are only on the 2nd (low level biome), 4th (random) and 5th (mid-high level biome) sections (no more lecturn rerolling, also only sells 3 books per restock)
Can now wear leather armour based on their level, changeable within their GUI
Buying or selling a lot of the same trade will cause its price to increase for a limited time
All diamond tool and weapon trades cost at least a diamond
Trading with a villager while riding a camel will have the villager take on the passenger seat until you trade with them again
Villagers always zombify but now turn into a nitwit based on the difficulty
The wandering trader now only spawns on natural blocks like grass
They buy and sell a larger variety of items, including a rare item of a mob head, music disc, trim, sherd or a map to a unique biome

Redstone:

Copper bulbs have a 1 game tick delay
Powering an amethyst blocks generates an artificial vibration based on the redstone signal strength
many of the redstone components have gotten a texture tweak to better show what it is doing (also brewing stand gui)
Redstone is better shown in the jungle temple and ancient city portal room (now also with the wither painting)
If you have the 1.21 experimental features enabled, the trial chambers will have a redstone door
The comparator output of an inverted daylight detector now reads the phase of the moon as the local difficulty increases with the less moon that is shown
Ores broken by an explosion have a chance to drop double

World Generation:

The ocean is twice as deep, bringing down ocean monuments, but now they have 8 diamond blocks rather than gold blocks, and the elders have a chance to drop an enchanted golden apple
Amplified terrain can now sometimes generate in the world normally
Certain biomes have more of a particular ore, shown by having other unique identifiers
Villages, ruined portal and ocean structures generate less often but strongholds can now generate infinitely
Eyes of ender can be used to find end cities
How to build a beacon is now shown in one of the woodland mansion rooms, conduits in underwater ruins, an iron golem at the pillager outposts and enchanting in the stronghold libraries
Igloo will always generate its basement, indicated via a red carpet

Mobs:

Parrots are less likely to fall off and can be grabbed mid air
Husks drop sand while converting into a zombie
Allays drop an echo shard and turn into a vex when killed by a wardens sonic boom
The iron golem spawning cooldown has been reduced to 20 seconds, however now each iron golem requires a new hostile mob and the villagers to consume a piece of food for the spawn to be successful
Music discs are now renewable to a certain capacity (creeper killed by piglin/shulker, creeper kills warden/sniffer)
Armour stands can be given arms via sticks and removed with shears

Other Other:

Fishing now has a bait power (no bait/spider eye/fermented spider eye) to determine the quality of the loot, including a medium loot table for items like ingots. The treasure loot table has been buffed with items like tridents and potions, including the luck potion which also now affects chest and mob loot.
The beacon effect provided is now based on what block the pyramid is made out of, which now includes lapis, copper, coal and ancient debris. Only need 3 layers now to unlock the second level, continuing to increase the size of the pyramid increases its range and it also applies to pets and mounts
If it is a full moon and you are on the surface, you have increased luck when fishing, farming gets a buff in the first quarter, looting when it is a new moon and fortune in the third quarter
The fletching table can be used more efficiently to craft arrows, including tipped arrows without the need for dragons breath Render distance fog has been thickened while the lava fog distance has been increased and can now be increased futher with fire protection
All the advancements have been brought onto the same page, some added/removed, buffed the xp reward of all advancements
Includes a built in resource pack for a dark UI and other tweaks that I personally like

Cubfans List:

Cube fireworks (craft with feather as it replaces burst fireworks)
Bees spread flowers upon pollination
Lingering potions can be thrown further
Awkward potion has a different colour

Fixed 1.0.4-1.20.4

Fixed 1.0.3-1.20.4

Fixed 1.0.2a-1.20.4

Fixed 1.0.2-1.20.4

Fixed 1.0.1-1.20.4

Fixed 1.0.0-1.20.4

Enchanting:

Base:

Enchanting table:

Anvil:

Netherite anvil:

Other:

Transportation:

Stamina:

Horses:

Minecarts:

Elytra:

Mapbook:

Boats:

Inventory:

Combat:

Snapshots:

Totems:

Other stuff

Phantoms:

Wither:

Dragon

Other

Villagers:

Redstone:

World Generation:

Mobs:

Other Other:

Cubfans List: