Ensnare

Contract

Aens is TFT CAbilityEnsnare (parent AAsm). ANen (Naga, TFT-only) and ACen (creep) are AbilityData aliases whose code is Aens, so they share CAbilityEnsnare and read their own rows through abilityitem_t.code. ACen is registered in s_skills.c.

Web (Aweb / ACwb, Bwea / Bweb) delegates to the same bind/height lifecycle with air-only validation and autocast. Removing one bind leaves flight grounded until the last Web or Ensnare slot is removed. Landing/restoration also updates targtype between ground and air, not only AI_FLYING. See creep combat effects.

Rawcode	Archive	Notes
Aens	ROC and TFT	Raider Ensnare
ANen	TFT	Naga Ensnare (code=Aens)
ACen	ROC and TFT	creep Ensnare (code=Aens)

Casting binds one living enemy/neutral unit so it cannot move for Dur / HeroDur. Air units lose AI_FLYING immediately so ground attacks can hit them, then descend to the support surface over DataA.

ROC vs TFT

Field	ROC Aens	TFT Aens
targs	ground,air,enemy,neutral	same
cool / rng	20 / 400	16 / 500
Dur / HeroDur	20 / 5	12 / 3
DataA / DataB / DataC	0.6 / 200 / 128	same
BuffID	empty	Bena,Beng

WorldEdit AbilityMetaData labels (WESTRING_AEVAL_ENS*):

Field	Stock	Meta name	Runtime
DataA	0.6	Air Unit Lower Duration	seconds to land (and to rise on expiry); <=0 snaps
DataB	200	Air Unit Height	land start height when DataA>0
DataC	128	Melee Attack Range	ensnared unit's attack range while bound

ROC omits BuffID; apply Bens (CBuffEnsnare) as the documented fallback (same pattern as empty Aams → Bams / empty Acyc → Bcyc). TFT BuffID=Bena,Beng selects Bena (CBuffEnsnareAir) for flyers and Beng (CBuffEnsnareGround) for ground units. Both are subclasses of Bens in the TFT class tree; move lock and land restore treat all three as ensnare.

Data Flow

AbilityData.slk (Aens / ANen)
  -> targs, Cost, Rng, Dur/HeroDur, BuffID, DataA-C
CAbilityEnsnare
  -> A_EXECUTE: unit_addtimedstatus(Bena | Beng | Bens fallback)
              store spell->code in status.data; begin land (DataA/B)
  -> A_UPDATE: advance land / rise FlyHeight; M_CheckGround
m_unit status machinery (storage, iteration, timing only)
  -> unit_expirestatus: A_STATUS_REMOVE to the owner resolved from
     status.data (origin rawcode); slot wiped after the owner runs
  -> unit_refreshstatusflags: stun aggregation plus A_STATUS_REFRESH to the
     owner of each remaining status
CAbilityEnsnare (owns AI_FLYING, phases, restoration)
  -> A_STATUS_REFRESH: ground while a bind remains, else restore flight
  -> A_STATUS_REMOVE: start rise when DataA>0, restore flight only when no
     other bind remains; runs before the slot wipe so authored data is valid
order_move
  -> S_UnitIsEnsnared / BEer reject movement
s_attack range
  -> S_EnsnareMeleeRange returns DataC while ensnared

Land uses buff age against DataA with start height DataB (else authored moveHeight). Rise after expiry stores DataA on the edict and lerps from 0 to authored moveHeight. Zero/missing DataA keeps the prior instant land-and- restore path so fixtures without those cells stay deterministic.

Diagnostic Workflow

build/bin/ability_audit -data 'data/Warcraft III' -raw Aens
build/bin/ability_audit -data 'data/Warcraft III' -raw ANen

Verification

make test-wc3-engine WC3_PATTERN='wc3_spell.ensnare*'

Focused tests cover alias procedure lookup, ground Bens move lock, flyer land-and-lock, gradual DataA/DataB descent, expiry restore of AI_FLYING/altitude, ground targets staying non-flying, recast refresh, dispel mid-land, overlapping binds, attack/move restoration, unrelated flight state, and save/load during land and rise.