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Chimera is the update to Halo: Combat Evolved for the PC that we should have had but never got.

It is licensed under version 3.0 of the GNU General Public License. See LICENSE for more information.

The official repository is hosted at

Table of contents


Here is the installation procedure for installing Chimera:

  1. Update Halo to version 1.10 (unless you're playing the trial).
  2. Back up your game's Strings.dll. Renaming it to strings-old.dll works.
  3. Copy strings.dll, chimera.ini, and fonts into your game folder.
  4. Optionally add a mods folder to load custom dll mods.

NOTE: Each file goes into the main game folder, NOT controls. If you put the files in controls, it will not work.

Uninstalling Chimera is simple:

  1. Delete Chimera's strings.dll and optionally chimera.ini, fonts, and/or mods.
  2. Rename your backed up copy of Halo's Strings.dll back to strings.dll.

Mod support

You can install binary mods (i.e. dlls) by creating a folder called "mods" and copying the dlls into the directory.

NOTE: Chimera does not support dll mods including HAC2 or Open Sauce. This is because they modify the game in similar ways, resulting in them conflicting with one another. Supporting just one of these mods would mean extra development time that we don't have. Sorry.


Chimera provides a number of features and enhancements to the base Halo game. To ensure the base game is preserved as much as possible, most features are not turned on by default, and the ones that are only exist to enhance or fix the game.

Passive features

These are features that are always on.


The game has an issue where object movement is tied to tick rate, thus objects will never move faster than 30 frames per second. Chimera adds interpolation to the game for objects. Unlike MCC, it also adds it for cutscenes and plasma projectiles, too.

Limit increase

Chimera increases some of the limits of the game. Note that, unless you play a map that exceeds these limits, your performance will not be impacted. If you don't have this on, then maps that exceed the limits will look incorrect and may not even be playable. Therefore, this feature is always on. Here are the increases:

  • BSP polygon limit boosted to 32767
  • Visible object limit boosted to 1024
  • Draw distance increased to 2250 world units (~6.86 km)

Compressed maps

Chimera supports Invader-compressed maps. This allows you to take advantage of the blazingly fast zstd compression algorithm, drastically cutting down map size.

If maps in RAM is enabled, compressed maps will be decompressed directly into RAM. Otherwise, temp files will be used (placed in Chimera's folder).

Camera shake fix

Chimera fixes a bug where camera shaking does not work at high frame rates.

Reduced DRM

Normally, Halo does not allow you to join servers with someone that has the same CD key. This was done to prevent people from sharing CD keys. However, this protection has shown to not work and, as a result, is purely an hindrance to people who have legitimate copies of the game, such as modders. By disabling the CD key check, you can locally host a game that lets you join yourself. Also, because a large number of players do not own legitimate copies of the game, having the CD key check in place will likely prevent you from getting any players in the first place.

Note that this feature does not "crack" the game. You still need a valid Halo installation in order to run the installer for the game as well as update the game to 1.10.

Descope fix

When you take damage while zoomed in, the game zooms back out automatically. This functionality is broken when in a server, as the client only descopes when the player takes damage on the client instance rather than if they actually took damage on the server. Chimera changes this to making it so if you lose health or shield, you are descoped.

Extended description fix

Chimera fixes a bug where the "About" button of the profile settings menu doesn't display the correct bitmap in the extended description.

Fast loading

Halo Custom Edition CRC32s every map on startup. On a small maps folder, this does not significantly increase loading time. On a massive maps folder, this drastically increases loading time, ranging from seconds to minutes.

Some mods "fix" this by storing the CRC32 in a cache, but this negates the point of it in the first place, as now you can join servers with mismatched CRC32s. Chimera truly fixes it by CRC32ing the map when you load the map, not the game.

Fast server listing

The game takes forever to query the master server. Chimera speeds it up.

128 MiB map leak fix

If you load a map that exceeds 128 MiB, the game opens the map multiple times and only closes it once. This results in the map leaking, and eventually, the game could run out of file descriptors. Chimera fixes this by removing the file size check.

Model LOD fix

The game uses your vertical resolution to determine how detailed to draw a model. However, this results in levels like The Pillar of Autumn showing the highest LOD for some mods when it shouldn't, leading to infamous glitches like the "4K headless chief" glitch. Chimera makes it scale by 480p, instead.

FOV fix

There is a bug in the game where, when you increase the vertical resolution of the game, your FOV gets slightly more narrow, even if you are on the same aspect ratio. Chimera fixes this so FOVs stay consistent between vertical resolutions. This does NOT fix low FOV at widescreen aspect ratios, which is what chimera_fov is for.

Sun fix

Lens flares are drawn at a set number of pixels regardless of vertical resolution. Chimera makes it scale by 768p, instead.

Custom chat

The Keystone chat is crashy and broken. Chimera adds a replacement chat.

NVIDIA camo fix

Chimera fixes a bug where, if the GPU is an NVIDIA graphics card, it uses alpha blended camo instead of the liquid camo shader.

Contrail fix

Chimera fixes a bug where contrails are bugged at high frame rates.

Motion sensor fix

Chimera fixes a bug where the motion sensor fade is incorrect at >30 FPS

Fog fix

Fog in maps such as Assault on the Control Room's sky fog now works as intended.

Model detail fix

The "detail after reflection" flag in model shaders now works as intended.

HUD numbers fix

HUD numbers are no longer drawn oversized if modified to be a higher resolution.

Weapon swap ticks fix

Weapons are now picked up with the correct timing when holding the action key.

Auto center fix

Chimera fixes a bug where the game does auto look centering based on frame rate. This would result in vehicles being difficult to handle at high frame rates.

Name fade fix

Names now fade in/out correctly at high frame rates when staring at a player.

Scoreboard fade fix

Scoreboard now fades in/out correctly at high frame rates.

Timer offset fix

Halo PC has a bug where equipment spawns floor(8.1n) ticks (where n = the netgame equipment index). This bug is fixed.

Sane default Halo settings

Halo's default video (not including resolution) and audio settings are set to more appropriate settings for modern PCs:

Setting New default Note

Removed update check

The check for updates that occurs when clicking on "INTERNET" in joining or creating games is disabled.

Removed Watson

When Halo PC crashes, it launches a program called "Watson" to attempt to report errors to a server that has not been online in years. This is a waste of time, and it presents a minor annoyance for people who are unaware that you can simply remove the Watson folder. Therefore, Chimera removes the functionality altogether.

Multi-team vehicles fix

Servers with Chimera's chimera_allow_all_passengers, multi-team vehicles, or some equivalent feature enabled will not desync a client with this fix.

Map downloading

Chimera will automatically attempt to download maps off of the HAC2 Map repo upon joining a server that is playing a map you don't have. A different map source can be configured using the download_template setting. These maps are stored under chimera/maps in your Halo profiles folder by default (see the download_map_path setting).

Lua scripting

Lua scripting ported from Chimera -572. Scripts in the global folder are loaded on startup. They remain permanently loaded unless the user uses the scripts reload command. Scripts in the map folder is loaded when a map is loaded and unloaded when a map is unloaded. Scripts may also be contained inside of map files.

Ini features

Chimera has a very customizable chimera.ini text file that you can use to further tweak your game.

Note that .ini comments start with a ; and some features are commented out (disabled) like so: ;enabled=1. This is so if you want to enable a feature, you simply have to remove the semicolon.

Below are the features you can take advantage of.

Halo settings

These features exist to modify how Halo is initialized.

  • path (changes the profile path location)
  • map_path (changes the path maps will be loaded from)
  • download_map_path (changes the path custom maps are downloaded to)
  • exec (changes the init text file loaded)
  • server_port (set the default server port)
  • client_port (set the default client port)
  • console (enable console)
  • main_menu_music (disables the music in the main menu)
  • background_playback (allow Halo to play in the background)
  • multiple_instances (allow Halo to spawn in multiple instances)
  • hash (set a custom hash or % for a random one)

Scoreboard settings

This exists to manipulate the scoreboard

  • font (change the font)
  • fade_time (change the fade in and fade out time)

Name settings

This exists to manipulate the names shown when looking at players.

  • font (change the font)

Memory settings

This feature exists to allow you to take advantage larger amounts of RAM, reducing hiccups and stutters, especially on slower storage. However, you will need an LAA-patched executable to use this feature.

  • enabled (enables loading maps directly into RAM)
  • map_size (size of buffer in MiB for loading maps)
  • benchmark (shows a benchmark whenever a map is loaded)
  • download_font (change the font used for downloading)
  • download_preferred_node (change the initial server node tested)
  • download_retail_maps (allow downloading of retail Halo PC maps - UNSAFE)

Font override settings

This allows you to override fonts Chimera uses with system fonts, allowing you to choose the size, family, drop shadow, and weight (boldness) of each font. See the included chimera.ini for more information on these. You can also optionally add a fonts folder to your game install location to use loose ttf, otf, and ttc files.

Video mode settings

These settings allow you to change Halo's video settings without requiring vidmode. You can even use refresh rates in excess of 120 Hz.

  • enabled (enables the feature)
  • width (default width in pixels)
  • height (default height in pixels)
  • refresh_rate (refresh rate in Hertz)
  • vsync (enable double buffer vSync to reduce tearing)
  • windowed (display Halo in a window)
  • borderless (display Halo in borderless fullscreen - required windowed mode)

Controller settings

These settings allow you to configure gamepads. See the included chimera.ini file for more information on these settings. You can also get [premade configs] in the Chimera repository if you want to use a premade configuration file.

Custom chat settings

This allows you to customize the different colors, positioning, and timings of Chimera's chat. When we said it was a custom chat, we meant it. See the included chimera.ini file for more information on these settings.


This allows you to execute Chimera commands, Halo commands, or Halo scripts when the key combination is invoked. See the included chimera.ini file for more information on these settings.

Custom Edition map support on retail

Chimera can enable Halo Custom Edition map support when playing the base Halo PC game.

To enable this, put the following files to your maps folder:

  • (Halo Custom Edition file)
  • (Halo Custom Edition file)
  • (Halo Custom Edition file)

You can obtain these files from the Halo Custom Edition installer. Then, simply rename them to have the custom_ prefixes and copy them into your maps folder.

NOTE: If you do not wish to install Halo Custom Edition, you can extract these resource map files from the installer using archiver programs such as 7-Zip (Windows) or p7zip (POSIX).

CAUTION: Do NOT overwrite your original or files. You need these to load Halo PC maps. Also, Chimera will not enable this feature if any of the above files are missing.


Chimera provides a number of extra features that can be turned on. Most of these features are off by default. Commands are stored in preferences.txt in the chimera folder created by Chimera.

Aim assist

Halo's aim assist was broken in the PC release. Chimera fixes it. It only works for analog sticks, though.

Usage: chimera_aim_assist [true/false]

Allow all passengers

Disable teammate restrictions for vehicles, allowing anyone to enter anyone's vehicle. This will only apply if you're hosting a game, and clients will need to have a version of Chimera that fixes desyncing with multi-team vehicles (or an equivalent mod), or else desyncing will occur.

Usage: chimera_allow_all_passengers [true/false]

Anisotropic filtering

This enables the same thing that is done in config.txt but without having to edit it. Note that this only applies to the level geometry, not individual objects. You'd need AF enabled externally to do that.

Usage: chimera_af [true/false]

Auto uncrouching

When on the ground, the game disabled crouching if the player was running at full speed. You can re-enable this behavior if you want.

Usage: chimera_auto_uncrouch [true/false]

Block all bullshit

This feature runs the following commands:

  • chimera_block_buffering 1
  • chimera_block_gametype_indicator 1
  • chimera_block_gametype_rules 1
  • chimera_block_hold_f1 1
  • chimera_block_loading_screen 1
  • chimera_block_zoom_blur 1
  • chimera_block_mouse_acceleration 1

Usage: chimera_block_all_bullshit

Block auto center

Set whether or not auto centering in vehicles is disabled.

Usage: chimera_block_auto_center [true/false]

Block buffering

This feature is known to reduce input lag, and it works like the feature in config.txt. You can enable this behavior if you want.

Usage: chimera_block_buffering [true/false]

Block button quotes

Remove the quotation marks in button prompts (e.g. Hold "E")

Usage: chimera_block_button_quotes [true/false]

Block equipment rotation

Netgame equipment rotation was added in Halo PC. You can disable it if you want spawns to look more like their Xbox counterparts, though most maps will probably look worse.

Usage: chimera_block_equipment_rotation [true/false]

Block extra weapon

Block your currently held weapon if you have more than two weapons. Unblock weapons with Unblock all extra weapons. This will last until the next game.

Usage: chimera_block_extra_weapon

Block gametype indicator

The original Xbox version of the game didn't have the gametype indicator, and it looks out of place in most custom maps. You can disable it, if you want.

Usage: chimera_block_gametype_indicator [true/false]

Block gametype rules

In Halo Custom Edition, if you join a server, you see the gametype rules for a few seconds (or part of a second depending on frame rate). If this is annoying, you can disable it.

Usage: chimera_block_gametype_rules [true/false]

Block hold F1

When you join a server, you'll see a "Hold F1 for score" (or whatever button is bound to score screens). You can disable this if you want.

Usage: chimera_block_hold_f1 [true/false]

Block letterbox

Cutscenes have a letterbox. You can disable it if you want.

Usage: chimera_block_letterbox [true/false]

Block loading screen

When you join a server, you are blinded for a few seconds by a loading screen, and this can make you susceptible to being cheaply killed. This disables that loading screen.

Usage: chimera_block_loading_screen [true/false]

Block mouse acceleration

Halo uses raw input, thus it bypasses the mouse acceleration setting of your operating system (unless you run the game in Wine). However, Halo adds its own mouse acceleration on top of direct input.

Usage: chimera_block_mouse_acceleration [true/false]

Block server IP

This hides the server IP from view in the score screen. This is good for streamers who don't want people to join what server they are in. You can enable this feature if you want.

Usage: chimera_block_server_ip [true/false]

Block zoom blur

Halo's zoom blur looks like ass on high resolutions. This feature removes it without requiring you to use DisableAlphaRenderTargets or safe mode.

Usage: chimera_block_zoom_blur [true/false]

Bookmark add

Add a server to the server bookmarks list. If no server details are given, then the last server joined is added. You can use a domain name in place of an IP.

Usage: chimera_bookmark_add [ip:port [password]]

Bookmark delete

Delete a server from the server bookmarks list. Either an index or an ip:port can be used. If no server details are given, then the last server joined is deleted.

Usage: chimera_bookmark_delete [ip:port | index]

Bookmark connect

Connect to a server in the bookmarks list.

Usage: chimera_bookmark_connect <index>

Bookmark list

List and query all bookmarked servers.

Usage: chimera_bookmark_list

History connect

Connect to a server in the recent server list.

Usage: chimera_history_connect <index>

History list

List and query all recent servers.

Usage: chimera_history_list


Show the different budgets in Halo, including object limit and BSP polygon limit.

Usage: chimera_budget [true/false]

Chat: Block IPs

Block IPs from being shown in the custom chat. This is good for streamers, so their IPs don't get shown on stream. It requires custom chat to be enabled.

Usage: chimera_chat_block_ips [true/false]

Chat: Block server messages

Block all messages from the server except for if you're using rcon in the console.

Usage: chimera_chat_block_server_messages [true/false]

Chat: Chat color help

Show fancy chat colors you can use.

Usage: chimera_chat_color_help [true/false]

Console prompt color

Set the console input color.

Usage: chimera_console_prompt_color [<red> <green> <blue>]


Set deadzones for analog input.

Usage: chimera_deadzones [0-1]

Delete empty weapons

Automatically delete empty weapons when hosting, similar to Xbox behavior.

Usage: chimera_delete_empty_weapons [true/false]


Enable devmode commands without blocking you from multiplayer or requiring any command line arguments.

Usage: chimera_devmode [true/false]


Set the diagonals for moving with an analog stick. This is because Halo converts it to digital input, as the netcode does not support analog movement. A good value is 0.75.

Usage: chimera_diagonals [0-1]


Set FoV. End with "v" to lock to a vertical FoV, or use "auto" to set to an automatic FoV. Using a vertical FoV over a horizontal one helps prevent the game from distorting your field of view when switching aspect ratios.

Setting chimera_fov_cinematic and chimera_fov_vehicle will apply their FoV when those apply, falling back to chimera_fov if they aren't set or not doing anything at all if chimera_fov is not set.

Usage: chimera_fov [degrees] Usage: chimera_fov_cinematic [degrees] Usage: chimera_fov_vehicle [degrees]

FP reverb

Set whether or not first person sounds should have reverberations when EAX is enabled.

Usage: chimera_fp_reverb [true/false]


Chimera is localized for both English and, thanks to help from the community, Spanish.

Usage: chimera_language [en/es]

Model detail

Change the model detail. Higher values increase LODs. This will not make models extra detailed. Instead, it will change the threshold for when higher LODs appear. Extremely high values will cause the aforementioned "4K headless chief" glitch, except at any vertical resolution this time.

Usage: chimera_model_detail [detail]

Mouse sensitivity

Set the mouse sensitivity. This is more granular than using Halo's settings. It is recommended to have mouse acceleration disabled if using low values.

Halo Horizontal Vertical
10 4 2
9 4 2
8 3 1.5
7 2 1
6 1.5 0.75
5 1.25 0.625
4 1 0.5
3 0.75 0.375
2 0.5 0.25
1 0.25 0.125

Usage: chimera_mouse_sensitivity [off | <horizontal> <vertical>]

Player info

Show player info for the given player.

Usage: chimera_player_info <player>

Player list

List player indices.

Usage: chimera_player_list

Send chat message

Send a chat message. Channel 0 is "all", channel 1 is "team", and channel 2 is "vehicle". Other channels may be used by mods.

Usage: chimera_send_chat_message <channel> <message>

Set color

Set your in-game color for free-for-all gametypes.

Usage: chimera_set_color [color]

Set name

Set your in-game name.

Usage: chimera_set_name [name]

Show coordinates

Show your in-game coordinates.

Usage: chimera_show_coordinates [true/false]

Show FPS

Show your in-game FPS.

Usage: chimera_show_fps [true/false]

Shrink empty weapons

Make empty weapons appear smaller so they're easier to spot.

Usage: chimera_shrink_empty_weapons [true/false]

Spam to join

Set whether or not to automatically reattempt connecting if the server is full.

Usage: chimera_spam_to_join [true/false]

Split screen HUD

Override the HUD with the split screen HUD.

Usage: chimera_split_screen_hud [true/false]


Spectate a specific player. Use 0 to disable spectating.

Usage: chimera_spectate <index>

Spectate next

Spectate the next player. This is intended to be used with hotkeys.

Usage: chimera_spectate_next

Spectate previous

Spectate the previous player. This is intended to be used with hotkeys.

Usage: chimera_spectate_back

Spectate team only

Set whether or not chimera_spectate_next or chimera_spectate_previous selects players not on the same team. This has no effect on non-team games.

Usage: chimera_spectate_team_only <enabled>


Teleport you or, if you're hosting a server, someone else to the given X/Y/Z coordinates or player.

Usage: chimera_teleport [#] <<#> | <x> <y> <z>>

Throttle FPS

Throttle Halo's frame rate. Set to 0 to disable.

Usage: chimera_throttle_fps [FPS]


Set the game's tick rate. This will not work outside of client hosted games.

Usage: chimera_tps [TPS]

Unblock all extra weapons

Unblock all weapons blocked with Block extra weapon

Usage: chimera_unblock_all_extra_weapons

Uncap cinematic

Uncap the cinematic frame rate from 30 FPS.

Usage: chimera_uncap_cinematic [true/false]

Widescreen fix

Fix the scaling of HUD, menu, and text elements for wider aspect ratios. This may break some maps, and this will not be fixed as fixing one thing will break another thing due to the nature of these fixes. Setting 1 has the HUD fill the screen, while setting 2 restricts the HUD to the center 4:3 area of the screen.

Usage: chimera_widescreen_fix [0/1/2]


Below is a list of frequently asked questions. These questions are either based on questions I have received or questions I might receive that I feel are worth answering in a readme.

Will Chimera run on my system?

Short answer: If your PC is semi-recent and uses Windows 10, it'll work. Note that, while Chimera isn't too taxing, especially on modern systems, it can make Halo harder to run if you're on extremely ancient hardware. We do not test Chimera on Windows XP, Windows Vista, Windows 7, or Windows 8(.1), but it will probably run on them, too.

Long answer: There are the requirements:

  • OS (if on Windows): Windows 10 or newer (Windows XP may work, but it is untested)
  • Wine (if on Linux): Wine 4.0 or newer*

*We test on the latest wine-staging 5.0 version, but 4.0 should work.

If your PC does not at least meet the above requirements, Chimera may fail to run properly due to the underlying API being older.

There are the recommendations for running Chimera optimally:

  • CPU (Intel): Intel Core i3-2100 (3.1 GHz) or better
  • CPU (AMD): AMD FX 6100 (3.3 GHz) or better
  • RAM: 8 GiB or more*
  • GPU (Nvidia): Nvidia GeForce 8500 GT
  • GPU (AMD): ATI Radeon HD 5670 or better
  • GPU (Intel): see Nvidia and AMD requirements

* Halo, even with Chimera, is 32-bit, so it won't technically use more than 4 GiB, but 8 GiB is recommended so Chimera has enough RAM.

The newest of the above recommendations is the AMD CPU (FX 6100) which was released in the year 2011 - over seven years ago at the time of writing this sentence.

Can I use Chimera under a license besides GNU GPL version 3?

Probably not. You would first need to ask all of the developers of Chimera for permission.

Why are my custom fonts not working?

This can occur when a required DirectX 9 library isn't installed. The fix is to download and run the official DirectX installer from .

Why does Halo's gamma setting not work when Chimera is installed?

Short answer: Halo's gamma setting was disabled as it does a lot more harm than good. Basically, it's screwed up and there's no good way to fix it. This may seem like an inconvenience, but you really do not want to use this. We recommend using dgVoodoo2 for this, instead.

Long answer: How Halo's gamma setting works is, rather than changing Halo's own brightness level, it changes your operating system's brightness. It then stores the gamma setting by editing the registry. Halo is then programmed to restore the operating system's older gamma setting when it closes. However, this can only occur if Halo closes correctly. There is the chance that it won't close properly (exception errors, you closed it improperly, etc.), and if that happens, you may end up with Halo's gamma setting lingering.

We decided to disable this setting since it presented unnecessary modifications to the registry, it potentially ends up actually screwing up your operating system's video settings, and there is quite simply a better way to do it, anyway.

We are not going to provide an option to re-enable it. Again, use dgVoodoo2, instead.

Why is there no auto updater built into Chimera?

Short answer: Auto updating is not actually a feature you want. For the best experience, the responsibility for keeping Chimera up-to-date falls upon you, the user.

Long answer: The gains of adding an auto updater are vastly outweighed by the cons of having one.

The only reason to add an auto updater is for convenience. Chimera is very easy to install and update. So, it is not necessary to add one even for novice users. Updates are generally announced on both the Discord server as well as on Open Carnage at

In fact, there are many reasons against having an auto updater built into the mod.

First, you need write access to the mod DLL. Chimera is written to be a single strings.dll. When the game is running, this file cannot be written to due to it being in use. This can be worked around by having Chimera, itself, be a separate DLL, but this would require rewriting how Chimera is loaded. We decided to use one DLL because a number of users ran into issues with it due to user error.

Also, most people do not have write access to the Halo: Combat Evolved game files as they installed it into the default "Program Files" folder. To bypass this, you would have to manually give yourself permission (too complicated for some users to figure out), or you run the .exe as an administrator (very foolish to do on an Internet-connected game from 2003 that more-or-less assumes that cache files are "safe").

Having an auto updater or even an update notifier would also require contacting a server whenever the game starts. Doing that increases startup time, and it is error prone.

For example, an auto updater presents a security risk. You're assuming that the server used to host the update is never going to be hijacked. Signing the update can be used to mitigate this, preventing unauthorized builds from being installed due to validation failing on the client side, but that's only effective if the signing mechanism is not compromised. Also, there's the chance that a developer could decide to go rogue and deliberately push a bad update out of spite. We would NEVER do that, but should you still take the chance?

Also, existing auto updater implementations in Halo mods have all proven to cause issues, some of which are actively killing the game.

For example, SAPP, a popular server mod, has auto updating. However, some versions would crash Halo with an exception error when run on Wine. The reason for the crash is due to how the mod developer obfuscates the DLL. Wine has issues loading these DLLs, requiring them to be unpacked. However, because the DLL has been tampered with, doing this is not possible without reverting the DLL manually.

As another example, HAC2, a popular client mod, also has auto updating. Periodically, the HAC2 server may go down, and for whatever reason, HAC2 was written to not allow the user to start the game with HAC2 if auto updating failed, resulting in the player base permanently being decimated. This behavior is not unlike "always online" DRM although the intentions are not malicious - it is merely an oversight (albeit an expensive one). In fact, HAC2's loader.dll does not even come with HAC2 and requires an initial connection to the Internet to work.

Newer versions of the HAC2 loader do not exhibit this issue, but many people use the older version of the loader as it's what's most distributed. Either way, the damage is done.

Also, at some point, the HAC2 project changed developers, and updates became closed source (the public HAC2 repository is not maintained and is years out of date, and it isn't even complete enough to build). This meant that people updated from a mostly free and open source build to a nonfree and closed source build.

No mod developer should be able to do any of the following:

  • Update to a build that no longer works when it was working before
  • Restrict you from playing the game unless it can communicate with a server
  • Change the terms of your agreement to said software without your consent

Also, no user should have the option to consent to any of the above, because absolutely nothing good comes from having it enabled.

Since it's easy to keep your version of Chimera up-to-date, anyway, it was decided against implementing auto updating functionality in Chimera.

Why do I get an error when joining Custom Edition servers with modded maps?

Short answer: This is probably due to a CRC32 mismatch. Basically, this is to prevent Halo from crashing due to using a map that differs from what is hosted on the server. This is done for your protection, and we recommend either forging the CRC32 or getting the original map.

Long answer: Halo Custom Edition (and Chimera if joining Custom Edition servers) calculates a checksum (a number) from your map based on the contents of the map file. It then sends this number to the server upon joining, and the server compares it against the map it has. If the checksum isn't forged, then it can confirm, with ~99.999999976% certainty (or a 1 in 4,294,967,296 chance for a collision), that the map is identical.

The reason it does all of this is due to the fact that using a modified map or a different map entirely can result in a game crash for the client. Obviously, there are some modifications that can be done to a map that will not result in a crash, but there is no way to discern such a chance using a checksum, alone. This is done for your protection, and it is not recommended to attempt to bypass this check.

If you want to join a server using a modified Halo Custom Edition map on a Halo Custom Edition server, then you should forge the CRC32.