Spawns and regions

All spawns

No spawn: Mini Boss, Strong Zombie, Fire Slime, Forest Guardian, Elite Skeleton, Specter.

Other mob sources

• Farms: an incubator on an island breeds mobs from DNA (Farms and incubators). Such mobs are tied to the incubator, not to a spawn point.
• Summon ability: a mob summons other mobs next to its target (e.g. the Mini Boss calls Strong Zombies). Summoned mobs have no limit, no spawn leash and no location check.
• An administrator can summon any mob with a command.

Lobby regions

The lobby map is divided into regions. A region is one or several rectangles, optionally limited vertically. A region determines the place name shown on screen, combat rules, and where mobs are scattered in area mode.

• The first matching region wins. Regions are checked in a fixed order. This is why Zombie Zone (the underground beneath Farpoint, checked earlier) is dangerous even though it lies inside the Farpoint safe zone.
• Safe zone: the player takes no damage at all (including from mobs) and is regularly healed to full.
• Mobs only (no PvP): mobs and the environment hurt, players cannot fight each other. It is enough that one of the sides stands in such a region.
• PvP: players can fight each other (Combat and PvP).
• Outside regions the terrain is called "Wilderness" and PvP applies there.
• Discovery: the first time you enter a region on foot, its name is shown full screen with a sound. Later visits are silent. The starting region, terrain outside regions and flying over a region discover nothing.

Within the lobby borders the map has 998,001 columns. Regions cover 718,848 of them (72%). Regions tightly cover the rectangle x -416 ... 415, z -416 ... 447, so "Wilderness" is only the strip between it and the map border (x -515 ... 483, z -495 ... 503).

Spawn points

A spawn point is a recipe: which mob, where, how many at a time and how often. The engine checks all points every second and reloads changes from the panel every 30 s without a restart. There are two modes:

• Point: mobs appear in a circle around the point, only when a player is nearby.
• Area: mobs are scattered across the whole region at one height, also in terrain where nobody is present.

Point mode

Every second, for each point:

1. If less than "interval" seconds have passed since the last attempt, nothing happens.
2. If the terrain at the center of the point is not loaded, nothing happens and the attempt is not used up.
3. The attempt is used up. It is then aborted by: wrong time of day, no player in range (straight-line distance, vertical included), no free room in the limit, a failed chance roll.
4. Free room = limit - living mobs from this point in loaded terrain across the whole world.
5. Mob count = random from group min to max, no more than the free room.
6. Each mob gets a location (section Location selection). If a location runs out for one of them, the rest of the group is lost until the next attempt.

Area mode

Every second, for each point:

1. The "interval", time of day, free room in the limit and chance work as in point mode. A player's presence is not needed.
2. A column is drawn up to 8 times: first a region rectangle weighted by its number of columns (a wider piece gets proportionally more mobs), then a column within it. Rectangles whose height range does not include the required foot height are skipped.
3. A column closer than 24 blocks to any player (straight line) is rejected. Drawing ends once as many columns have been collected as mobs are needed.
4. A column in unloaded terrain is briefly loaded in the background and held until the mob is placed. Then the terrain releases itself and saves the mob. The mob "sleeps" there until a player arrives.
5. A column is suitable only if the block under the feet is solid and, from the feet upward, there are as many free blocks without water and lava as the mob needs. We do not search higher or lower: in the canyon that would mean climbing onto an edge or into a wall. An unsuitable column is lost.
6. The placed mob remembers its location as its home: it patrols around it and returns to it.

Alive limit in area mode

Mobs scattered across the whole region usually lie in unloaded terrain, so they cannot be counted as in point mode. Every placed mob is recorded in a limit memory that survives a restart:

• a mob's death or removal frees room in the limit; unloading terrain and a player leaving do not;
• a mob seen in loaded terrain refreshes its entry (saved every 5 minutes);
• an entry not seen for 7 days is removed (checked every 30 minutes) - this is a mob that vanished without a trace.

Example: Ghost in the Borderlands region

Required foot height: y = 2. The share applies to the column draw; columns where it is impossible to stand at that height are lost, so where the canyon floor lies higher or lower there are fewer mobs. Going from zero to the full limit of 45 mobs takes at least 225 s (one mob every 5 s).

Location selection and collisions

A mob never appears inside a block. The required free height depends on the mob's scale:

Point mode

1. A random point in a circle of the given radius, uniformly across the whole circle area.
2. In that column, ground is searched for: first from the point's height downward, then upward, by at most max(radius; 3) blocks. Ground is a solid block with the required number of free blocks above it, without water and lava. Searching from below makes a mob in a cave stand on its floor and not above its ceiling.
3. A column in unloaded terrain is skipped.
4. Up to 12 point draws. With no result, the mob does not appear in this attempt.
5. The placed mob is checked once more using its real hitbox. If it intersects a block, it disappears in the same moment (the player will not see it) and a new location is searched for, up to 12 times.

Spawn leash and chase

A mob from a spawn defends its piece of the map and does not chase a player across the whole world. Every second, for each mob in loaded terrain:

• A mob farther from the center than the chase boundary loses its target and walks back to the center.
• A mob farther than the boundary + 48 blocks (e.g. pushed or stuck) teleports to its place: in point mode to a free spot within the point's radius, in area mode to its home.
• A mob does not target anyone standing farther from the center than the chase boundary. A player beyond the boundary is invisible to it, even when shooting the mob.

Patrol

A point with a patrol range greater than 0 sends its mobs on walks:

• Only a mob with no attack target and no assigned path, in loaded terrain, goes for a walk.
• The gap between walks is 30 +- 10 s (random 20–40 s) and is counted for the whole point: in one gap, one mob from this point goes for a walk.
• Walk destination: point mode - a random spot within the patrol range around the point, chosen like a spawn location; area mode - up to 8 random columns within the patrol range around home, only those where the mob will stand at its foot height.
• The mob walks on foot, avoiding obstacles. It does not pass through blocks.

To be decided

• Regions without mobs. Ashspire, Dark Forest, FallenKeep, Hidden Camp, Sentinel Hill, SilenceForest, SkyHopper, SnowMountain, SnowValley, Winterwatch have no spawn at all. Today mobs appear only in the Borderlands and Zombie Zone regions.
• Patrol per point, not per mob. One walk every 20–40 s falls to the whole point. When 45 Ghosts from one point are loaded, each of them moves on average every 22.5 minutes while the rest stand still. To decide: a separate rhythm for each mob.
• Several lobby instances. Spawn points are assigned to a world name, so they work separately on each instance that has such a world. In point mode each instance counts its own mobs. The area-mode limit memory is shared: after a restart an instance counts other instances' mobs toward the limit, and after 7 days removes their entries that it cannot see itself. To decide: a limit per instance.
• Mobs from terrain without players. In area mode mobs appear even when nobody is on the server; terrain is briefly loaded. With many area points this is a constant cost for the server.
• Region name spelling is inconsistent: SilenceForest, SnowMountain, SkyHopper and FallenKeep are written as one word, while Dark Forest, Hidden Camp, Sentinel Hill and Zombie Zone have a space.
• Region description is filled in only for Farpoint and Zombie Zone.