BACAPtimized

Singleplayer (instance): default version of the modpack designed to fit for most of the players

• Advancements Reloaded - enlarges advancement screen and shows incompleted criteria for any advancement
• Async Particles - optimizes particle rendering
• Auto Clicker - can be used for afk at farms that require attacking / fast jump statistics farming (don't forget your regeneration beacons for long afk sessions). Old one
• Better Block Entities (1.21.8+ only) - optimizes rendering of block entities (chests, shulker boxes, beds, etc) and makes them visible regardless of distance from the player
• Better Statistics Screen - adds search bar to statistics screen and makes it more clean
• C2me - optimizes server side of chunk loading and generating
• Chunky - allows you to pregenerate chunks with /chunky command
• Cloth Config - library for advancements reloaded, gamma utils, more culling
• Consistent Advancements - applies alphabetical sorting for advancements, so they don't shift up or down every relog
• Don't Hide My Items - adds bundle tooltip that always shows all items and their amount
• Dynamic FPS - lowers cpu and gpu usage when the game is running in the background. Note that it also lowers the sound volume, you should configure that if its important to you
• Entity Culling - culls entities that are not visible. This doesn't affect entity count in your F3, but culled entities don't show on the pie chart (modpack's config contains list of entities that shouldn't be affected by culling to be always visible at pie: Wandering trader, Trader llama, Skeleton horse, Llama, Panda, Wolf, Fox, Mooshroom, Chicken, Zombie Nautilus, Ender pearl, Arrow, Armor stand, Lightning bolt, Player, Ender dragon)
• Fabric API - main fabric library, used by many mods
• Fabric Language Kotlin - library for Auto Clicker and Bac Tracker mods
• Fast Noise (1.21.11+ only) - optimizes world generation
• Ferrite Core - lowers server side ram usage
• Gamma Utils - lets you overwrite brightness setting for fullbright (bind needed hotkeys in settings)
• ImmediatelyFast - optimizes gui and hud rendering
• Ixeris - optimizes mouse polling
• Lithium - optimizes server side game logic
• Modern Fix - lowers client side ram usage
• Mod Menu - allows you to see and configure installed mods
• More Culling - optimizes block states and leaves rendering
• Nvidium - optimizes terrain rendering. Works only with nvidia gpus 16 series or newer, does nothing with amd gpus. Incompatible and automatically turns off with Vulkan rendering
• Reese's Sodium Options - adds search bar to sodium settings and makes them appear on the left instead of top
• Show All Advancements - makes it possible to look through all advancement trees without completing first ones. Works only if installed on server side, hidden advancements are still hidden
• Shulker Box Tooltip - lets you view all contents of any shulker box with pressing shift while hovering it
• Sodium - optimizes rendering of everything. While using e-ray don't forget to turn off "Use Fog Occlusion" and "Use Entity Culling" (not included in the modpack's configs because it would reset your own already configured sodium stuff)
• Sodium Extra - lets you configure things like fog, particles, block animations
• TCD Commons - library for better statistics screen mod

Optional mods: see in 4th installation step

Deprecated: atum mod no longer updates, you can just disable some qol mods from singleplayer version and take extra ones from optional_mods folder

Speedrunning version: allows you to reset worlds with automatically installed bac
Speedrunning mods are taken from https://mods.tildejustin.dev\
All the versions are stable: marked as beta only for difference in the list

• Advanced Advancement Save - saves your advancements more frequently than on every pause. Mainly needed in speedruns for bac tracker to update faster
• Advancements Reloaded - enlarges advancement screen and shows incompleted criteria for any advancement
• Advancement Screenshot - takes screenshot every time you get an advancement
• Atum - allows fast random seeds resetting
• Auto Clicker - can be used for afk at farms that require attacking / fast jump statistics farming (don't forget your regeneration beacons for long afk sessions). Old one
• Bobby - downloads server chunks directly to your pc to simulate higher server view distance. Can be used in coop runs with lowered server render distance for better performance. Only works when joining servers and takes your additional disk space
• C2me - optimizes server side of chunk loading and generating
• Chunky - allows you to pregenerate chunks with /chunky command
• Cloth Config - library for advancements reloaded
• Collective - library that adv screenshot mod needs
• Consistent Advancements - applies alphabetical sorting for advancements, so they don't shift up or down every relog
• Dynamic FPS - lowers cpu and gpu usage when the game is running in the background
• Fabric API - main fabric library, used by many mods
• Fabric Language Kotlin - library for Auto Clicker and Bac Tracker mods
• Fast Noise (1.21.11+ only) - optimizes world generation
• Fast Reset - makes resetting with atum faster by not saving the worlds
• Ferrite Core - lowers server side ram usage
• ImmediatelyFast - optimizes gui and hud rendering
• Lithium - optimizes server side game logic
• Modern Fix - lowers client side ram usage
• Mod Menu - allows you to see and configure installed mods
• Nvidium - optimizes terrain rendering. Works only with nvidia gpus 16 series or newer, does nothing with amd gpus
• Planifolia - sets brightness setting limit to 500% instead of 100%
• Show All Advancements - makes it possible to look through all advancement trees without completing first ones. Works only if installed on server side, hidden advancements are still hidden
• Simple Resource Loader - grabs datapack zips from .minecraft/resources/datapack/required/ and adds them to every singleplayer world you join (needed for resetting, resources folder with datapack is included in this modpack too, you just need to copy it over)
• Sodium - optimizes rendering of everything. For F3 counter to be correct turn off both "Use Entity Culling" and "Use Fog Occlusion" (not included in the modpack configs because it would reset your own already configured sodium settings)
• Speedrun IGT - tracks and displays your in game and rta times in a configurable way. Doesn't work on servers

Optional mods folder:

• Advancement Info - original mod for showing incompleted advancement criteria, provided as alternative to advancements reloaded mod
• BAC Tracker - See more here. Other links: mod port to 1.21.10, original tracker

Server version: for server owners (put all stuff in server "mods" and "config" folders). Players that join don't need for those mods to be installed. Also if you are hosting a bac world on your own pc you might install those mods along with singleplayer/speedrunning version for even better server side performance
All the versions are stable: marked as alpha only for difference in the list

• Alternate Current - optimizes redstone dust up to 30 times. The only known issue: breaks specific tnt duper design
• C2me - optimizes server side of chunk loading and generating
• Chunky - allows you to pregenerate chunks with /chunky command
• Consistent Advancements - applies alphabetical sorting for advancements, so they don't shift up or down every relog
• Fabric API - main fabric library, used by many mods
• Fabric Carpet - adds /profile command for easy tracking what makes the most lag (only operators can use it by default). Also automatically adds tps/mspt bar in tab list for every player (changeable in config)
• Fast Noise (1.21.11+ only) - optimizes world generation
• Ferrite Core - lowers server side ram usage
• Lithium - optimizes server side game logic
• Scalable Lux - optimizes performance of light updates
• Show All Advancements - makes it possible to look through all advancement trees without completing first ones. Works only if installed on server side, hidden advancements are still hidden
• Spark - advanced performance profiler to identify the cause of performance issues
• TT 20 - makes some events faster while server tps is below 20 to make lags not that noticable. Known issue: shield/spear behaviors are inconsistent
• Very Many Players - improves server performance at high playercounts

Optional mods folder:

• Advanced Advancement Save - saves all players advancements more frequently than every 5 minutes. Mainly needed for bac tracker to update faster
• BAC Tracker - See more here. Other links: mod port to 1.21.10, original tracker
• Fabric Language Kotlin - library for Bac Tracker mod

The modpack will already work, but there's extra optional features with more mods (that are not for everyone)
There's additional "optional_mods" folder in "mods". Manually move needed JARs from there to your original mods folder

• Advanced Advancement Save - saves your advancements more frequently than on every pause. Might be useful in speedruns for bac tracker (only for exe version) to update faster. Warning: some people reported increased container contents showing delay with that mod installed
• Advancement Info - original mod for showing incompleted advancement criteria, provided as alternative to advancements reloaded mod
• Advancement Screenshot - takes screenshot every time you get an advancement. Some people might consider this a screenshot folder spam so it's not included by default
  Collective - library that adv screenshot mod needs
• BAC Tracker - See more here. Not for everyone because of relatively long installation and some players might prefer original exe tracker
  Fabric Language Kotlin - library for Bac Tracker mod (moved to regular mods folder in 1.21.11+)
• Bobby - downloads server chunks directly to your pc to simulate higher server view distance. Can be used in coop runs with lowered server render distance for better server performance. Only works when joining servers and takes your additional disk space
• Fast Server Pings - makes server list display info (ping) faster
• Better Vanilla F3 - makes F3 order consistent (pre 1.21.9 behavior) but keeps ability to configure it with F3+F6
  Yet Another Config Lib - library that Better Vanilla F3 mod needs
• Simple Resource Loader - grabs datapack zips from .minecraft/resources/datapack/required/ and adds them to every singleplayer world you join. Warning: don't uninstall this mod once you start playing, otherwise your advancements will reset
  (resources folder with datapack is included in this modpack too, you just need to copy it over)
• Speedrun IGT - tracks and displays your in game and rta times in a configurable way. Doesn't work on servers

While I can provide settings file for default minecraft with options.txt, I'm not doing it as it will reset your already pre configured options. It's impossible to make settings good for everyone because of different preferences.

Configurations that you might like to do:

• Graphics: Fast, Weather: Fast, Vignette: OFF, VSync: OFF, Max Framerate:
• Disable "Use entity culling" and "Use fog oclussion" in "Performance" tab if you care for entity counter in F3 to be correct (not related to 1.21.11 as its bugged and always shows 0/x even on vanilla: MC-304705)
• Disable dimension fogs in "Render" tab with "Atmospheric Fog" option (Warning: removing lava fog is not allowed by AL role rules on official BAC discord server)
• Change Gamma Utils keybinds if needed (by default changing brightness is G+Up and G+Down)
• Set 2 SpeedrunIGT keybinds to "None" to not accidentally reset timer
• Can add sound mute for unfocused and invisible states in dynamic fps mod settings through mod menu (be careful AFKing at farms if you decided to mute the sounds)
• Run /scoreboard objectives setdisplay sidebar bac_advancements command to turn on displaying amount of completed advancements on the sidebar (same command but without "bac_advancements" disables it)
• If you care about shaders or using some specific unicode symbols on signs: set "experimental_sign_text_buffering" to false in Immediately Fast mod config (can be found in .minecraft/config folder)

1. Make a backup of your world for safety if you screw anything up
2. Leave your world for more safety and don't go in during the process
3. Delete the old datapacks COMPLETELY from your world
4. Copy and paste in the new updated datapacks
5. Go into your world
6. If you screwed up, go to your backup, make a backup of your backup, then repeat steps 2-6 on the backup

Game crashes

All crash logs are saved in .minecraft/crash-reports. There're 2 types:
Client - your world is correctly saved upon crash.
Server - usually rolls back to one of latest saves.
Use https://stackdeobf.net to make logs more understandable.
Use https://mclo.gs/ to share logs for getting help.
The only known crash that could happen before is geometryPlanes (fixed in 26.1 v1.2). You can get updated nvidium for older versions on github releases or temporarily disable it in place you're consistently getting crash in

Java crashes

You can differentiate java crashes if no crash report was created in regular .minecraft/crash-reports. Instead you will get hs_err_pid????.log in .minecraft.
If your log mentions Current CompileTask: io.netty.util.internal.ReferenceCountUpdater::retryRelease0 (70 bytes), add -XX:CompileCommand=exclude,io/netty/util/internal/ReferenceCountUpdater,retryRelease0 to your java arguments to prevent from crashing later

Minor differences

1. root.tick.entities pie chart fluctuates and can vary by changing view without moving - singleplayer version.
   Fixed starting from 1.21.11 v1.11, copy Entity Culling config from the folder if you need it on older versions
2. Block entities render from any distance - singleplayer version.
   Better Block Entities make it render from any distance (doesn't affect root.tick.blockEntities in pie chart)
3. No chunk fade - singleplayer, speedrunning versions.
   Not supported by Nvidium
4. 5-10% worse max fps on lower than 16 chunks render distance - singleplayer, speedrunning versions.
   Nvidium thing, you won't notice this ever because even the worst supported gpu gets 400+ fps on that rd which is more than enough to hit monitor's refresh rate; meanwhile on 32 rd it does 50% fps boost
5. Extended nether fog - singleplayer, speedrunning.
   Nvidium had that bug until 1.21.6, if you're above and still getting that, check Sodium Extra settings
6. root.tick.blockEntities may be different from vannila - singleplayer, speedrunning.
   Lithium intentional thing. Doesn't ruin possible uses of pie raying
7. Specific tnt duper design is broken - server version.
   Use an alternative duper provided from the thread or disable Alternate Current mod
8. Shield / spear behaviors are inconsistent - server version.
   TT20 bug. Fixed starting from 26.1 v1.1

• Clarification: those changed mechanics will most likely be unnoticed by most of the modpack players. And for those who will encounter it, difference will be minimal. It's statistically worth to include those mods. This list was made for troubleshooting if you encountered such a problem (and proves that modpack is well researched)

Vanilla bugs

Not related to modpack but you can vote in provided links if you want Mojang to fix them

• Destroyed ender pearls respawn from player data on re-login (MC-306936). 1.21.2(?)-current. Hard to reproduce but happens in singleplayer too
• Double/shift clicking in inventory is too responsive (MC-301852 + MC-303393). 1.21.9-current
• Various mob AI search ranges are now random (MC-301649). 1.21.2-current
• Client food item stack desync when picking up food after eating (MC-241851). 1.17-current
• [Fixed] Entity counter in F3 doesn't work (MC-304705). 1.21.11 only. If you're getting wrong entity counts on any other version: disable "Use entity culling" and "Use fog oclussion" in "Performance" tab
• [Fixed] Zombie villagers spawn as the variant matching the biome at 0, 0, 0 (MC-302516). 1.21.9-1.21.10
• [Fixed] Zombie villagers convert biome to one in which they were cured (MC-307266). 26.1_snapshot_1-26.2-snapshot_5
• [Fixed] Nether portal hitbox is too small (MC-295395). 1.21.5 only
• [Fixed] Dragon quarters the damage even if hit in head (MC-308469). 1.21.4-26.3
• [Fixed] Sprint crouching and 45 strafes are deleted (reverted MC-152728 + MC-271065). 1.21.4 only