Lethal Company’s mod scene is the largest of any co-op horror game on Thunderstore: 27,595 packages, of which 4,585 tag themselves client-side, 3,103 server-side and 1,451 are entire moons. That size is exactly why “best mods” lists fail people. The mods at the top of the download chart are mostly libraries — code other mods call — so installing them by hand gives you no new content and one more thing that can version-mismatch.
This page separates the three things people actually mean by “mods”: the plumbing, the quality-of-life layer, and the content.
Install path that does not break
- Install r2modman (10,762,572 downloads, last updated 29 October 2026). It handles BepInEx, profile isolation and dependency resolution in one step, which manual installs do not.
- Create a profile per group you play with. Profiles are the only clean way to keep a vanilla lobby and a modded lobby on the same machine.
- Install mods from inside the manager, not from browser downloads. The manager pulls dependencies; a manual download does not.
- Launch the game through the manager. Launching from Steam loads the vanilla install and none of your mods.
If you insist on manual installation, BepInEx-BepInExPack (34,058,821 downloads — the single most-installed package on the community) is the loader everything else depends on, and it must be placed by hand before any other mod will load.
The top of the chart is plumbing
| Rank | Package | Downloads | What it actually is |
|---|---|---|---|
| 1 | BepInExPack | 34,058,821 | The mod loader |
| 2 | MoreCompany | 27,067,305 | Raises the 4-player lobby cap, adds cosmetics |
| 3 | LethalLib | 24,088,919 | Framework that content mods register against |
| 4 | ReservedItemSlotCore | 22,823,592 | Core for the dedicated item-slot mods |
| 5 | LethalCompany_InputUtils | 19,713,758 | Keybind library |
| 6 | TooManyEmotes | 17,949,333 | 300+ emotes, emote wheel, masked enemies emote |
| 7 | More_Suits | 17,485,031 | Suit loader and suit library |
| 8 | ReservedFlashlightSlot | 16,297,804 | A dedicated flashlight slot on the HUD |
| 9 | Mimics | 14,333,362 | A monster that disguises itself as scrap |
| 10 | LethalLevelLoader | 13,270,031 | Framework for custom moons and interiors |
Read that table as a dependency tree rather than a shopping list. Ranks 1, 3, 4, 5 and 10 are infrastructure. Ranks 2, 6, 7 and 9 are the ones a player would notice.
The five-mod quality-of-life set
If you want the game to feel better without changing what it is, this is the QoL layer to install. Every entry here is client-side or safe-server, so one player can run them without forcing the group to match.
- ReservedFlashlightSlot (16,297,804) and ReservedWalkieSlot (12,416,477) — dedicated slots so the flashlight and walkie do not eat inventory grid space. This is the single largest quality-of-life gain in the game because it removes the “who took my walkie” argument.
- BetterStamina (6,672,350) — tunes stamina regen and consumption and softens the speed penalty. Server-side tagged, so the host decides.
- Coroner (7,247,973) — adds cause of death to the performance report. Client-side, and it turns “what killed me” from a group debate into a line of text.
- HotbarPlus (5,705,007) — hotbar slot count and behaviour tweaks.
- CullFactory (5,895,937) — stops rendering interior rooms that are not visible. This is the performance mod, not a gameplay one.
Client-side, server-side, host-only
This is the part that decides whether your lobby loads. Thunderstore tags every package, and the tags are not decoration:
- Client-side — each player installs it for themselves. One player having More_Suits does not break a lobby where nobody else does.
- Server-side — the host’s copy defines the lobby. If the host has it and you do not, you will be rejected.
- Host — only the person hosting needs it.
The practical rule: agree the server-side set first, install it identically, then let everyone add client-side cosmetics and HUD mods on top. A group that swaps this order spends the evening reinstalling.
Content mods actually worth the slot
- Mimics (14,333,362) — a monster that looks like scrap until you pick it up. It is the highest-download pure-content mod on the community for a reason: it attacks the one habit every experienced player has, which is grabbing scrap without looking.
- FacilityMeltdown (4,657,008) — pulls the apparatus and starts a countdown. Turns a routine apparatus run into a timed escape.
- Orion (5,194,929) — a full custom moon. Moons are the deepest content category here: 1,451 packages, and each one is a complete level rather than a tweak.
- NeedyCats (5,869,779) — cats that roam the facility. Light, and it survives balance changes because it does not touch combat.
The mods people search for by name
Some queries are specific enough that the honest answer is a single package name and a download number, so:
| Search | The mod | Downloads | Note |
|---|---|---|---|
| Yippee mod | sunnobunno-YippeeMod | 9,096,324 | Replaces Hoarding Bug chitter with the yippee sound. There is also YippeeScrap (1,151,518) which adds a yippee as collectable scrap |
| Skinwalker / voice mimic | qwbarch-Mirage | 6,430,960 | Voice mimicking where every player hears the same voice, aimed at masked enemies |
| VR mod | DaXcess-LethalCompanyVR | 1,155,260 | Client-side headset support, not a full VR port |
| Xenomorph mod | TheMetaMeister-Xenomorph_Playermodel | 7,587 | A playermodel, not a creature. Several Xenomorph suits exist; none of them add an alien enemy |
| Boombox controller | KoderTeh-Boombox_Controller | 4,464,499 | Load a track into the boombox by link |
| Emote mod | FlipMods-TooManyEmotes | 17,949,333 | The 300+ emote pack, plus an emote wheel |
| Gun mod | MegaPiggy-BuyableShotgun | 4,627,960 | Shotguns in the store for 700 credits. BuyableShotgunShells (5,152,642) adds 20-credit shells |
Two honest notes on that table. The Xenomorph category is cosmetically popular but functionally tiny — the largest package has 7,587 downloads, four orders of magnitude below the top mods, so do not expect a working Alien creature. And the original LethalThings is delisted; what circulates now is HQ_Team-LethalThingsReloaded (27,321), a fork, not the mod that old videos showcase.
Prebuilt modpacks, and why they are a gamble
Thunderstore hosts modpacks as ordinary packages, and the popular ones are big: AudioKnight-StarlancerMoons (2,721,069) bundles four moons — one free, one intermediate, one late-game, one hidden — and sfDesat-Explorations (1,791,041) is a moon collection. lethal_coder-Lethal_Enhanced_Party_Edition (303,563) is a full curated pack with a core module and separate cosmetics.
If you want a whole evening’s worth of content in one click, a modpack is the right tool. The trade-off is version lag: a modpack is only as current as its last update, and one outdated dependency inside it can stop the lobby from loading. Check date_updated before you build a group’s evening around one.
When a lobby refuses to load
Work down this list; it resolves most cases in under two minutes.
- Version mismatch. The host updated a server-side mod and a client did not. The manager shows a mismatch warning before launch — read it instead of clicking through.
- Wrong launch path. Someone launched from Steam rather than the manager, so their client is vanilla joining a modded host.
- Player count. Vanilla caps at four. A fifth player needs MoreCompany on both sides, not just the host.
- Profile drift. Two people in the same group installed “the same mods” at different times. Export the profile from the manager and import it, rather than comparing lists by eye.