Signature (‘EFF ‘)

Version (‘V2.0’)

External EFFs - the field is the same as the signature field from the header
Embedded EFFs - this field is zeroed out

External EFFs - the field is the same as the version field from the header
Embedded EFFs - this field is zeroed out

Opcode number

Target type

• 0 ⟶ None
• 1 ⟶ Self
• 2 ⟶ Projectile target
• 3 ⟶ Party
• 4 ⟶ Everyone
• 5 ⟶ Everyone except party
• 6 ⟶ Caster group
• 7 ⟶ Target group
• 8 ⟶ Everyone except self
• 9 ⟶ Original caster

Power

Parameter 1

Parameter 2

Timing mode

• 0 ⟶ Instant/Limited
• 1 ⟶ Instant/Permanent
• 2 ⟶ Instant/While equipped
• 3 ⟶ Delay/Limited
• 4 ⟶ Delay/Permanent
• 5 ⟶ Delay/While equipped
• 6 ⟶ Limited after duration
• 7 ⟶ Permanent after duration
• 8 ⟶ Equipped after duration
• 9 ⟶ Instant/Permanent (after Death)
• 10 ⟶ Instant/Limited
• 4096 ⟶ Absolute duration
  • Effect is applied instantly.
  • This timing mode treats the Duration field as the effect’s expiration time (in ticks). Expires at Gametime(ticks) >= Duration(ticks).
    If the Duration field is 108000, the effect will expire when the game timer reaches 24 hours, or instantly if the game timer has already passed that point. 108000 = 300(1 hour) * 24 * 15 (ticks ➔ seconds).

Duration

• This field is measured in seconds or ticks (¹⁄₁₅ second), depending on Timing mode.

Probability 1

Probability 2

Resource

Dice Thrown

Dice Sides

Saving throw type

• bit 0 ⟶ Spells
• bit 1 ⟶ Breath
• bit 2 ⟶ Paralyze / Poison / Death
• bit 3 ⟶ Wands
• bit 4 ⟶ Petrify / Polymorph
• bit 10 ⟶ Ignore primary target (EE only)
• bit 11 ⟶ Ignore secondary target (EE only)
• bit 24 ⟶ Bypass mirror image (EE/TobEx only)
• bit 25 ⟶
  • Ignore difficulty (EE only)
  • Limit effect stacking (ToBEx only)
• bit 26 ⟶ TobEx internal (don’t use)

Save bonus

Special (EE games)

TobEx: Stacking ID. Checked when bit 25 of the Saving Throw Type is set.

If two effects of the same opcode are applied, both have Limit Effect Stacking bit set, and both have the same stacking ID, then the latter applied effect is suspended in application until the former effect expires. Regardless of whether it is applied, the latter effect will expire at the same time that it would expire if it was applied. In other words, the total duration of some non-stacking effect opcode is not extended because more than one copy of the effect was applied.

Stacking IDs are unique to the opcode being applied. To maintain uniqueness of stacking IDs between different mods, one recommendation is to use the higher word of Special as the modder’s Infinity Engine Community Prefix, then use the lower word as an identifying ID. For example, 0x41360001 (‘A6’ 0x0001).

Primary Type (School)

• See MSCHOOL.2DA.

Dispel/Resistance

The default behaviour is that effects cannot be dispelled and ignore resistance.

• bit 0 ⟶ Dispel
  • Can be dispelled, affected by Magic Resistance.
• bit 1 ⟶ Bypass resistance
  • Ignores Magic Resistance.
• bit 2 ⟶ Bypasses deflection/reflection/trap opcodes (only in EE games patched to v2.0+).
• bit 3 ⟶ Self-targeted (only in EE games patched to v2.6+)
  • Targeting yourself with an ability (Extended Header) will internally set this bit on all effects applied by that ability.
    • For the caster, it will allow a Magic Resistance check for any effect that has both Dispel set and offers some saving throw.
      • The saving throw doesn’t have to succeed, it just has to be offered.
    • For anyone else hit by the ability, it will allow a Magic Resistance check for any effect that also has Dispel set.
  • Either way, this bit is still overridden by Bypass Resistance.
  • This feature should eliminate the bug/exploit of bypassing other’s Magic Resistance by targeting yourself with an area-effect ability.
• bit 31 ⟶ Effect applied by item
  • Effect was applied by an ITM (only present in EE games patched to v2.0+).
  • It is set by the engine if the effect’s source ITM is identified.
    • This bit is only used by opcode #324 which checks it to determine whether it should set STRREF_FEEDBACK_IMMUNE_RESOURCE to the ITM’s general or identified name.

This can also be presented in the more traditional way:

• 0 ⟶ Nonmagical
• 1 ⟶ Can be dispelled/Affected by resistance
• 2 ⟶ Cannot be dispelled/Ignores resistance
• 3 ⟶ Can be dispelled/Ignores resistance

Parameter 3

Parameter 4

Parameter 5

Time applied (ticks)

• It stores the gametime (ticks) at which the effect was originally applied.

Resource 2 (VVC in many effects)

Resource 3

Caster X coordinate

Caster Y coordinate

Target X coordinate

Target Y coordinate

Parent resource type

• 0 ⟶ None
• 1 ⟶ Spell
• 2 ⟶ Item

Parent resource

Parent resource flags

• bit 10 ⟶ Hostile
• bit 11 ⟶ No LOS required
• bit 12 ⟶ Allow spotting
• bit 13 ⟶ Outdoors only
• bit 14 ⟶ Non-magical ability
• bit 15 ⟶ Ignore Wild Surge
• bit 16 ⟶ Non-combat ability

Projectile

Variable name

Caster level

Secondary Type

• See MSECTYPE.2DA.