Every meaningful pickup in the Lands Between is a check. The map is carved into regions and each one is sealed behind an item the multiworld has to hand you.
Pure runtime — no game files are patched, nothing is baked per seed. Delete the client and Elden Ring is exactly as you left it.
An Elden Ring slot is large enough to change everyone else's evening, and most of the settings that matter are about that. The builder tells you what your seed will do before you generate it.
Computed from the region tables and your actual options: how many checks, how many regions kept, how many of those checks can hold progression. Exact, with the spread shown rather than a median pretending to be a promise.
A live readout, on every step, of how much of your pool is open to a foreign item and
how much stays home — and it responds to the knob people actually reach for,
filler_foreign_pct.
Where no exact answer exists it says so instead of printing a figure that never moves.
Seven tabs, every option described in the words it was written with rather than its internal tag name. The yaml it writes records which apworld version it was built for, so a host can always tell which build a file came from.
The world is Shattered. Its 29 regions — 17 in the base game, 12 in Shadow of the Erdtree — are each sealed behind an Archipelago item called a Region Lock. You start at Roundtable Hold with one region open. When a Lock arrives from the multiworld, that region's graces light up on your map and you warp in. Walk toward a region you do not hold the Lock for, by any route, and you are put back at Roundtable Hold.
Vanilla routes and vanilla key items gate nothing. You never need the Rold Medallion to reach the Mountaintops; you never fight Mohg to enter the Land of Shadow. Elden Ring's go-anywhere map becomes a progression puzzle, and the region you open next is usually somewhere you would never go next in an ordinary run.
The item pool is curated, and not by your choice. A recipe called
curated_filler spends the entire junk end of the pool — every check that would
have paid a Rune or a junk consumable — and by default puts roughly two fifths of it back as
real weapons, armor, spells, talismans and Ashes of War. So vanilla items will be missing from
your seed, and that is the design, not a bug. It ships on. The builder's Checks & Item
Pool tab is where you reweight it, and weighting junk tells it to keep whatever
each check already paid.
num_regions — how much of the map is in play. 0 is the
full Shattering; 4 is a tight evening. The goal region is always kept, so every
seed is winnable.curated_filler — the recipe above. Nine category weights, relative
rather than percentages; juice is the real-gear share.keep_local — which categories of item stay in your own world, so a
five-player game does not turn into four people opening your crafting materials.confine_foreign_progression — a percentage, not a switch: how much of
what you send out is allowed to be the good stuff.Six things, and the builder is the one to start with. You can finish in the builder and press Generate & host, and the seed is generated and the room is started here — one small box in Helsinki, which is plenty for a few friends and an evening. For a long game with people you do not share a Discord with, take the yaml and use archipelago.gg: it has the uptime and the room history, and this does not.
Every option, explained, with your seed's size computed as you go. Downloads a finished yaml.
The player bundle — apworld, client and docs in one zip — and the bare apworld for hosts. Take both halves from the same release.
Setup, the player guide, known issues, and the recipe for stacking thefifthmatt's randomizer for enemies and starting class.
Generate from the builder in one click, or upload a .archipelago you made
yourself. Each room gets its own port and keeps it, so the address you hand your friends
still works next week.
A room sleeps when nobody has been connected for a while; press Start to wake it. While it sleeps no address is shown, because nothing is listening on it — and an address that is shown is one you can trust.
All 4,931 catalogued checks, searchable and filterable by region, with a map. If one is attributed to the wrong region, the report button fills the issue out for you — with the evidence attached and no verdict claimed on your behalf.
A form that asks for the things every report needs anyway: the release tag you took both
halves from, your whole yaml, the log from the last SESSION START, and what
else was loaded.
No GitHub account needed. It hands you a finished report to paste into Discord, or opens a prefilled issue if you would rather.
Active development, roughly a release a day, driven mostly by playtest reports. Traps, DeathLink and grace attunement are all off unless you ask for them; enemy scaling is on and keyed to your progression rather than to the map.
🛑 The DLC is in by default. Every preset in the builder except
vanilla_deathlink turns it off, and so does the yaml shipped in the release —
but a bare options block leaves it on. If you do not own Shadow of the Erdtree, say
enable_dlc: false rather than trusting a default.
The known-issues list in the release bundle is honest, including the by-design behaviours that get reported as bugs. If something looks wrong and is not on it, that is worth a report.