EternalTD Waves & Enemies

A wave file under plugins/EternalTD/waves/ defines the entire enemy lineup for a level, including normal waves, sudden-death waves, and optional pre-wave or wave messages. Each level config references one wave file through wavesConfigFile:.

Top-Level Fields

Field	Type	Default	Notes
isEnabled	bool	true	Disabling here also disables the level that depends on this file
baseMobAmount	int	20	Default amount used when an entry doesn't specify amount=
waveEntities	string list	required	Wave-by-wave enemy entries
suddenDeathWaveEntities	string list	optional	Optional cyclic wave pool that runs after the configured waves are exhausted
prewaveMessages	list of maps	optional	Messages shown before a specific wave starts
waveMessages	list of maps	optional	Messages shown when a wave begins

If the wave file does not define any sudden-death entries, the level ends as soon as the configured waves are exhausted.

Wave Entity Entry Format

Each line in waveEntities (or suddenDeathWaveEntities) is a colon-separated entry:

- wave=1:entityType=ZOMBIE:healthMultiplier=1.0:amount=10
- wave=2:entityType=SKELETON:fast:treasure
- wave=5:entityType=WITHER_SKELETON:boss
- wave=8:entityType=PHANTOM:air:horde

Key	Type	Notes
wave	int	Required. Wave number this entry belongs to
entityType	enum	Required. Bukkit EntityType enum value
healthMultiplier	double	Optional, default 1.0. Multiplies the entity's max health
amount	int	Optional. Overrides baseMobAmount for this entry
name	string	Optional. Custom name string. Parsed and stored, but the plugin does not currently apply it to the spawned mob (nameplates are the health/armor bars instead)
resist	flag	Marks the entity as slow-immune
fast	flag	Increases movement speed
treasure	flag	Doubles the gold bounty on kill
boss	flag	Spawns as a single boss with scaled health and a boss bar
horde	flag	Doubles amount and halves health
air	flag	Entity spawns 4 blocks above the path and ignores ground walls

Internal Quantity Math

• amount is incremented by wave / 10 and then truncated back to a whole number, so an entry with amount=20 yields 21 mobs at wave 15 and 22 at wave 20.
• boss entries override amount to max(1, floor(wave / 10)).
• horde entries double the final amount.
• On top of the per-entry amount, the wave runtime adds duplicates when the wave is built. Note that the list it indexes into is the fully expanded mob list — the config parser has already emitted one object per mob, so a single amount=20 line contributes 20 consecutive indices, not one. For each even index i (0, 2, 4, ...) that is both a valid index in that expanded list and smaller than the wave number, one extra clone of the mob at index i is added. Boss entries are never cloned this way. So the number of bonus mobs is roughly ceil(min(waveNumber, listSize) / 2): 1 extra mob at wave 1, 2 at waves 3-4, 5 at waves 9-10, 8 at waves 15-16, and so on until the wave number outgrows the list.

Spawn cadence inside a wave is min(200 / totalEntities, 20) ticks, and the runtime waits twice that before releasing each mob. horde waves halve the gap, releasing their mobs at double the normal rate. Every mob picks one of the level's start tiles at random when it spawns.

Message Block Format

Both prewaveMessages and waveMessages accept a list of maps:

prewaveMessages:
  - wave: 1
    message:
      - "&aWelcome! Build a couple of basic towers along the path."
  - wave: 5
    message:
      - "&6Heads up: a boss is coming next wave."

prewaveMessages runs at the start of the construction phase for that wave. waveMessages runs the moment the defensive phase begins.

Wave Lifecycle

A session moves through these states:

• STARTING — before the player runs /etd start for the first time.
• CONSTRUCTION_PHASE — 10-second build window between defensive phases.
• DEFENSIVE_PHASE — enemies are spawning and walking the path.
• ENDING — player quit, lost, or the level ran out of waves.

The construction phase always lasts 10 seconds unless the tutorial holds it (see Tutorial Level).

Wave end behavior:

• Completing a wave grants waveNumber * 10 gold.
• If you lost no lives during the wave, you receive a "Perfect" bonus worth half the wave bonus (waveNumber * 10 * 0.5). The announced number and the gold actually granted now match.
• Each wave can only pay out once — a wave that somehow reports completion twice is ignored the second time, and no payout happens at all once the session is ending.
• The next wave's modifier list is announced after each wave end.

When a Level Ends

The session advances only if the next wave number exists as a key in waveEntities, so wave numbers must run contiguously from 1. When the next number is missing:

• if the file defines suddenDeathWaveEntities, the run rolls into sudden death;
• otherwise the level ends immediately, without counting the wave that never ran. The persisted high score and the completion title use the last wave the player actually played.

Sudden Death

If suddenDeathWaveEntities is defined, the level keeps running past the configured wave list.

The sudden-death pool cycles by configured wave number, not by a running counter: each time a sudden-death wave is needed, EternalTD picks the lowest wave= number in the pool that is greater than the current one, and wraps back to the lowest configured number when there is nothing higher. The pool therefore does not need to be numbered 1, 2, 3, ... — gaps and arbitrary starting numbers cycle correctly.

The displayed wave number keeps counting up from the regular wave list; only the pool entry that gets spawned cycles.

Elemental Attunement on Wave Entities

Each wave has its own elemental attunement that rotates per wave:

• Wave 1 → Fire
• Wave 2 → Air
• Wave 3 → Water
• Wave 4 → Earth
• (then repeats)

When a wave entity spawns, there is a waveNumber / 100 chance that the entity inherits the wave's elemental attunement, displayed as a colored tag floating above the mob.

Elemental damage rules are handled by the tower's DamageTower class:

• Same attunement attacker vs same attunement target — 0.5× damage (resist).
• Opposite single elements (Fire vs Water, Air vs Earth) — 2× damage (crit).
• Fusion attunements (Magma, Blast, Storm, Sludge) follow paired interactions; see source for the full matrix.
• An unattuned tower deals 1× damage to everyone.

Fusion attunements form when a Basic Tower is touched by support towers with combining elemental attunements:

Combination	Resulting fusion
Fire + Earth	Magma
Fire + Air	Blast
Water + Air	Storm
Water + Earth	Sludge

The conflict rules are narrower than they look:

• Earth + Air on the same tower always reverts it to Unattuned, whatever else is attached.
• Fire + Water reverts to Unattuned only when three or more distinct attunements are in play. A tower touched by exactly one Fire support and one Water support keeps one of the two arbitrarily, because the code falls through to "pick the first attunement in the set" and that set is unordered.
• Unattuned support towers (Spyglass, Gold Mine) never affect the result; they are dropped from the set as soon as any attuned tower is attached.

Health, Armor, and Bounty Scaling

WaveEntity applies these steps at spawn, in this exact order:

1. Base health starts at 0.5 and grows with the wave: health = 0.5 + ((wave - 1)^1.2) / 2.
2. Boss entities multiply that by baseMobAmount × 0.5.
3. Horde entities halve it.
4. Bounty is computed here, as ceil(health) — before healthMultiplier and before the air penalty. treasure entries then double it.
5. maxHealth = health × healthMultiplier.
6. Air entities halve maxHealth again.
7. Armor only appears from wave 10 onward, set to maxHealth / 80.

The ordering in step 4 matters: a healthMultiplier of 3.0 triples an enemy's health without changing its gold payout, and air enemies pay the same bounty as their ground equivalents despite having half the health. Gold Mine support towers add their bonus to the bounty at the moment of the killing blow.

Movement speed is:

speed = 0.3 × (1 - slow)
        × 1.5 × (1 - slow)   if fast
        × 0.5                if air
        + wave / 1000

The trailing wave / 1000 term means enemies get very slightly faster every wave regardless of their flags, and it is applied after the air and slow multipliers rather than being scaled by them.

Splitterlings

From wave 20 onward, non-air enemies spawn additional small mobs ("splitterlings") on death.

• Count: floor(wave / 20) per kill.
• If the parent was a CAVE_SPIDER, the splitterlings are SILVERFISH. Otherwise they are CAVE_SPIDER.
• Splitterlings spawn at wave / 2 of the parent's wave, so a deep enough run can still chain a splitterling into more splitterlings on its own death.
• Splitterlings give 0 gold on death and air enemies never spawn splitterlings.

Tutorial Level Special Case

The bundled tutorial map runs through a hardcoded tutorial wave script:

• The construction phase does not auto-end until you have placed the exact required towers on the highlighted squares.
• Hardcoded towers are indicated by colored concrete patches under the targeted grid square and, if FMM is installed, a downward red arrow model floating above it.
• The tutorial injects extra gold on early waves so the scripted tower lineup is always affordable: +100 on waves 1, 2 and 3, and +200 on wave 4. Later waves get nothing extra.
• Each required tower square is coloured by the tower it wants: green concrete for Basic Tower, brown for Barricade, white for Sugar, cyan for Spyglass, yellow for Beam Generator, red for Explosion Factory, blue for Ice Box, gray for Armor Crusher, orange for Gold Mine, purple for Obsidian Quarry, black for anything else.

Player Lives and Gold

• Starting lives: 20.
• Starting gold: 150.
• Boss mobs cost 5 lives if they reach the end. All other mobs cost 1 life.
• Cheating (/etd cheat) sets gold to 10,000,000 and lives to 1,000,000, and marks the session as cheated for highscore purposes. Toggling cheat mode back off does not restore the original values, and the cheated flag is permanent for that session.
• /etd setwave <n> also sets the cheated flag, and rebases the wave-reward guard so the wave you jump to still pays out when it completes.

Highscore Tracking

Each level config persists highscoreWave and highscorePlayerName. At the end of a non-cheating session, the plugin saves the new wave number into the level file and broadcasts a server-wide message if it beat the previous score.