About ExtendedBosses
From ThunderstoreRaid-style boss fights from vanilla parts only: HP phases, add waves, nests, lieutenants, shields, burn windows, threat - seen by every player, mod or not.
ExtendedBosses
Raid-style boss fights for a group, from Eikthyr to Fader: HP phases, waves of adds, destructible nests, biome mini-bosses as lieutenants, shields that drop when the nests fall, burn windows, marks, ground hazards, resistance shifts and a threat table — built only from vanilla prefabs, animations and RPCs, so players without the mod see and feel the same fight.
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| | Eikthyr marks a player for lightning — spread out! | The Elder: roots under the marked player, a seed grows a new nest |
Phase announcements — every player sees them, with or without the mod
- Profiles
Light(bosses with reinforcements),Raid(default) andHard, globally
or per boss; any boss can be set back to Vanilla. Everything switches without a rejoin.
- Group scaling for 1–8 players: boss HP, adds, nests, stars and marks grow with the
group; solo stays doable.
- Reward on top of the vanilla drop: coins and valuables, about a stack of each
material of the biome, about half a stack of the next biome's, and upgraded gear of the next biome for a group of 2+.
- English and Russian messages; players without the mod get them in the language set
by GuestLanguage.
- The server's settings apply to every client with the mod; config edits are picked up
without a restart.
Install on the host; guests do not need it. With the HostOwner mod (Bosses = true) the host keeps owning the boss whoever hits it. On a dedicated server every player who may own the boss needs the mod.
Early version: every boss is implemented, in-game testing is in progress — the numbers are starting values and all adjustable.
How a fight goes
The boss's own attacks and AI stay vanilla — everything below is added on top. Described for the default Raid profile.
- Nests. As the fight goes on, the boss raises destructible spawners of its biome —
greydwarf nests, bone piles, eggs…
- Shield. While the nests stand, the boss takes only a fraction of the damage.
Break them all → the boss is staggered and takes ×1.5 damage for 10 s. Ignore them and the shield crumbles on its own after a while — without the bonus.
- Phases. About once a minute the boss enters a special state for 30 s — armor
against one damage type, regeneration, damage reflection… The message in the centre of the screen tells you how to answer it.
- Marks. The boss names a player and 3 s later strikes where they stand. Step away
from your friends.
- Lieutenants. Mini-bosses of the biome join the fight, along with waves of adds.
- Reward. On top of the vanilla drop: coins and valuables, about a stack of each
material of the biome, about half a stack of the next biome's, and upgraded gear of the next biome for a group of 2+.
Light keeps the adds and nests but drops shields, phases and marks; Hard is Raid, denser and tougher. All the numbers: FIGHTS.md.
The bosses
Eikthyr — the tutorial
No shield and no phases: every mechanic once, gently.
- Charge — every 20 s he dashes at double speed at a player who keeps their distance.
- Skull pile — raises Meadows skeletons until you break it (it glows for players with the mod and drops nothing).
- Lightning mark — the marked player is struck 3 s later.
- Reinforcements: boars and necks, and a herd leader — a 2★ boar with triple health.
The Elder
- Greydwarf nests hold his shield.
- Roots — roots burst out around the marked player.
- Seeds — his projectiles sometimes take root and grow a new nest.
- Living bark (phase): Sap — only slashing hits (axes, swords) get through;
Back — armored in front, full damage from behind: the tank keeps him facing away from the group.
- Shamans heal him — kill them first.
- Reinforcements: a troll, a bear, greydwarf elites, a skeleton and a ghost.
Bonemass
- Bone piles hold his shield.
- Leeches come out of the water nearby; poison pools under marked players; his
hits leave you Wet, later Tared.
- Merging — blobs crawl towards him from afar, and each one that reaches him heals
him. Intercept them.
- Phases: Hardening — blunt barely hurts, fire does double: burn him. *Rot
vapour* — close hits are halved and poison the attacker: fight from range.
- Reinforcements: an abomination, writhans, surtlings, elite draugr, a wraith and
swamp bats.
Moder
- Ice stalagmites hatch drakes and hold her shield. More drakes fly in all fight long.
- Ice nova under marked players — frost and slow.
- Breath mark — she lands and fixes on the marked player for a few seconds.
- Phases: Ice armor — while she is on the ground, ranged hits do a quarter: get
into melee. Ice spikes — every hit reflects part of its damage back as frost.
- Reinforcements: a wolf pack (ulvs at night), cultists, a stone golem, a fenring.
Highlights
From source dataLoaders
Runs on BepInEx.
Footprint
Rated a light load on a server.
Last update
Its author last shipped an update 7d ago.
ExtendedBosses on Nxeon
From our catalogue- One-click install
- Supported on Nxeon Valheim servers, for BepInEx servers. We download it from Thunderstore, place it, and restart the server.
- Server side
- Required on the server
- Server type needed
- BepInEx
- Server load
- light
- Smallest plan we suggest
- Valheim — 4 GB (4 GB RAM). This follows our own load rating above, not a benchmark.
- Latest build
- 0.8.17, released 2026-10-27
Game versions by loader
| Loader | Game versions | Newest |
|---|---|---|
| BepInEx |
From 7 recorded builds of ExtendedBosses.
Recent builds
| Build | Released | Game versions | Loaders |
|---|---|---|---|
| 0.8.17 | 2026-10-27 | n/a | BepInEx |
| 0.8.15 | 2026-10-25 | n/a | BepInEx |
| 0.8.14 | 2026-10-17 | n/a | BepInEx |
| 0.8.13 | 2026-10-17 | n/a | BepInEx |
| 0.8.11 | 2026-10-03 | n/a | BepInEx |
| 0.8.6 | 2026-09-26 | n/a | BepInEx |
Dependencies
- Required: BepInExPack Valheim
Declared by the newest build that lists any. Required ones are installed with it on one-click installs.
Run ExtendedBosses on a Valheim server
Pick a server or deploy a new one above; it is installed in one click.
What kind of mod it is
From the catalogCreatures & NPCs
Adds or changes creatures, NPCs and how they behave.
Runs on your server
From source side supportThunderstore lists ExtendedBosses as required on the server. Check its Thunderstore page to see whether players need it too.
Compatibility
- Game
- Valheim
- Loaders
- BepInEx
- Runs on
- Serverrequired on the server
- Requires
- One-click install needs a BepInEx server.
Verified at the source
- ✓ThunderstoreOfficial listing, checked 2026-10-28Open ↗
- ✓Authorj1gA, as published on Thunderstore
- ✓LicenseNot published by the sourceFree






