World spawn
How a new world picks a dry, level spawn near settlements and away from hostile structures, and where arriving players land.
A new Overworld chooses its own spawn instead of taking the first land vanilla finds. It searches up to 3072 blocks from the world centre for dry, fairly level ground on a real landmass, favours a village within walking distance and keeps away from hostile structures. Players who arrive at the world spawn then land on a safe block rather than a random one.
What a spawn must have
These are the default rules. Every number here is a setting; see World spawn configuration.
| Rule | Default |
|---|---|
| Search area | Up to 3072 blocks from 0, 0, sampled every 48 blocks |
| Ground height | 2–64 blocks above sea level; ground more than 40 blocks up scores lower |
| Relief | At most 9 blocks of height difference within 10 blocks |
| Water | None at the sample points 10 and 24 blocks out; water sampled within 32 blocks lowers the score, ocean counts twice |
| Landmass | At least 0.85 of the land samples at 96 and 192 blocks must be dry land |
| Distance | Full score within 768 blocks of the centre, half score 768 blocks further out |
| Village | A village 64–512 blocks away raises the score by up to 35% |
| Hostile structure | A pillager outpost, woodland mansion, ancient city, dragon roost, boss arena or similar within 160 blocks leaves 10% of the score |
| Stand checks | At most 12 of the best candidates are generated to look for a safe block |
Ocean, river, mushroom fields, Deep Dark and the three peak biomes are never chosen. Plains, meadows and the Great Plains score highest; deserts, jungles, swamps, badlands and snowy biomes score lower. The World Tree, Halo Crown, Sentinel Isles, Verdant Knives and every exotic terrain family are excluded.
Choosing the spawn
The search runs once, when the world is created, and only in the Overworld. It works in three passes.
-
Survey the land. Columns on a jittered grid are scored in widening square rings around the centre, straight from the terrain generator, without generating a single chunk. Each column is turned away by the first rule it fails. The survey stops once no farther ring could beat what it already has, and stops widening after
24000columns. -
Weigh villages and threats. The best
32columns are checked against where structures will generate, again without generating chunks. A village nearby raises a column; a hostile structure nearby sinks it. -
Find a stand. Starting from the best column, the area within
12blocks is generated and searched for the most comfortable block. The first column with one becomes the spawn.
What counts as a safe block
A stand is the highest ground in its column that is not leaves, with a full top, no fluid underneath for two blocks and two open blocks above. It must also be somewhere a mob could walk: no fire, lava, water edge or damaging block beside it. Ground inside a protected landmark footprint is never used. Among the safe blocks, the spawn prefers level neighbours, open sky, dirt-type ground and the middle of the area.
When a village was found, the world spawn faces towards it. A bonus chest, if you asked for one, is placed at the chosen spawn.
When nothing fits
If no column meets the rules, or none of the checked candidates has a safe block, the server log records why and the world uses vanilla spawn selection. The same happens when the settings are invalid, when spawn selection is turned off, and when the Overworld generator has no terrain to survey, such as a superflat world. Debug worlds always use vanilla selection.
Arriving at the spawn
A player joining for the first time, or respawning without a bed or respawn anchor, lands on a safe block inside the spawnRadius game rule around the world spawn. Every column in that square is tried once, in random order, and the first safe block wins. If there is none, the search widens to 24 blocks around the world spawn. If that also fails, vanilla placement takes over.
- Beds and respawn anchors are untouched. Only arrivals without one are placed.
- Adventure mode as the world’s game mode keeps vanilla placement.
- Other dimensions keep vanilla placement.
Checking a spawn
Both commands need permission level 2 and work in the Overworld whichever dimension you are in. /ise is the short form of /isekaiexpansion.
| Command | Result |
|---|---|
/ise spawn survey | Runs the survey and village pass without generating chunks. Prints the number of columns surveyed, the best 5 candidates with their score and biome, and how many columns each rule turned away. |
/ise spawn relocate | Runs the full search, generating chunks as needed, and moves the world spawn to the result. If nothing fits, it reports why and leaves the spawn where it is. |
Each candidate’s coordinates are clickable and suggest a teleport. A candidate marked as near a settlement found a village in range; one marked as near a hostile structure found a threat. The rejection counts name the rule: outside the border, water, volcanic, elevation, terrain, biome, shoreline, relief or landmass.
Other mods and settings
| Interaction | Behaviour |
|---|---|
| Biome Spawn Point, Village Spawn Point | Both replace the world spawn after this one has chosen it. The server log warns at startup when either is installed; remove them to use these rules. |
| Terrain families | Scored by family ID. Great Plains score 1.2, Luminous Grove and Starlit Glade 0.6 and Amber Basin 0.3. The World Tree, Halo Crown, Sentinel Isles, Verdant Knives and the exotic families are excluded. |
| Worlds without the pack’s terrain generator | Surveyed through the vanilla noise generator instead. Terrain family weights then have no effect. |
| Existing worlds | Keep their spawn. Use /ise spawn relocate to run the search on them. |
Where the settings live
All rules are in the spawn section of config/isekaiexpansion.json, owned by the server. Every option, its range and what an invalid value does are in World spawn configuration. The terrain families it weighs are described in Terrain and landmarks.