WML Abilities

The more complex abilities and weapon specials often consist of two parts:

• The ability / weapon special, which is only a dummy to provide a description and to see whether a unit has this ability. It is something one gives to a unit. Mainline abilities / weapon specials only need this part.
• One or multiple [event]s, which make things happen. These [event]s must be added to the game explicitly, in addition to the unit with the ability / weapon special!

How to include [event]s?

• Add it directly to the scenario file.
• Add it directly to the [era].
• Add it inside a [unit_type] definition.
• Add it inside a [resource].

If you add it both via an [era] and and the scenario, they are added twice … i.e. the pickpocket ability would give the gold twice! To avoid that, give each event an id. This is even mandatory when adding it in a [unit_type].

Even better would be to use a [resource]. Resources have also an id, so there will never be duplicates:

• Instead of adding it to the scenario / era, you add the event code inside a [resource].
• The same way you read the scenario / era file, you also read the file containing the [resource] tag.
• In the scenario / era, use load_resource.

Knockback

When a unit is hit with a knockback attack, it is immediately pushed back one hex away from the attacker. Units cannot be knocked back into an occupied hex, out of villages or onto terrain they normally could not move to. Only works on offense.

Use this to display the special correctly on the attacks you want:

#define WEAPON_SPECIAL_KNOCKBACK
    [dummy]
        id=knockback
        name= _ "knockback"
        female_name= _ "female^knockback"
        description=_ "When a unit is hit with a knockback attack, it is immediately pushed back one hex away from the attacker. Units cannot be knocked back into an occupied hex, out of villages or onto terrain they normally could not move to. Only works on offense."
        active_on=offense
    [/dummy]
#enddef

And insert this event to your [scenario], [multiplayer], [unit_type] or [era]:

[event]
    name=attacker hits
    first_time_only=no

    [filter_attack]
        special_id=knockback
    [/filter_attack]

    [filter_second]
        [not]
            [filter_location]
                terrain=*^V*
            [/filter_location]
        [/not]
    [/filter_second]

    [if]
        [variable]
            name=second_unit.hitpoints
            greater_than=0
        [/variable]

            [store_locations]
                [not]
                    [filter]
                    [/filter]
                [/not]

                [filter_adjacent_location]
                    x,y=$x2,$y2
                    adjacent=-$unit.facing
                [/filter_adjacent_location]

                variable=knockback_target_hex
            [/store_locations]

            [if]
                [variable]
                    name=knockback_target_hex.length
                    greater_than=0
                [/variable]

                [then]
                    [teleport]
                        [filter]
                            x,y=$x2,$y2
                        [/filter]

                        x,y=$knockback_target_hex.x,$knockback_target_hex.y
                        ignore_passability=no
                    [/teleport]

                    [if]
                        [have_unit]
                            x,y=$knockback_target_hex.x,$knockback_target_hex.y
                        [/have_unit]

                        [then]
                            [sound]
                                name=fist.ogg
                            [/sound]

                            # the knockbacked unit doesn't seem to receive experience by default,
                            # so we need to add it manually
                            [store_unit]
                                [filter]
                                    x,y=$knockback_target_hex.x,$knockback_target_hex.y
                                [/filter]

                                kill=yes
                                variable=knockbacked
                            [/store_unit]

                            {VARIABLE_OP knockbacked.experience add $unit.level}

                            [unstore_unit]
                                variable=knockbacked
                                text= _ "knockback"
                                {COLOR_HARM}
                                advance=true
                            [/unstore_unit]

                            {CLEAR_VARIABLE knockbacked}
                        [/then]
                    [/if]
                [/then]
            [/if]

            {CLEAR_VARIABLE knockback_target_hex}
        [/then]
    [/if]
[/event]

Charm

temporary

When a unit is hit by a charm attack, it instantly jumps to the attacker's side, and returns to its original side at the end of the turn. A charmed unit has 1 movement point and can attack.

Example that makes all Troll Whelps have charm on their attack:

{CHARM (type=Troll Whelp) fist}

#define CHARM FILTER WEAPON
    [event]
        name=attacker hits
        # Works only as attacker.
        # If you want to make a weapon special for this event, set:
        # [dummy]active_on=offense, then the engine greys out the weapon special on defense.
        first_time_only=no
        id=charm_as_attacker

        [filter]
            {FILTER}
        [/filter]

        [filter_attack]
            name={WEAPON}
            # or special_id=charm, if you create a [dummy] weapon special
        [/filter_attack]

        [filter_second]
            # If the leader is charmed, it might end the scenario,
            # as the other side is now considered defeated without a leader.
            # Better exclude leaders.
            canrecruit=no
            # If the unit would die from the damage,
            # we should not interfere with the event.
            formula="self.hitpoints > 0"
        [/filter_second]

        # Charm the unit
        # Changing the side will also immediately stop the combat and grant both units XP
        [modify_unit]
            [filter]
                x,y=$x2,$y2
            [/filter]
            [variables]
                # to remember the original side
                real_side=$second_unit.side
            [/variables]
            [status]
                # optional, just to easier find the unit in the other event
                charmed=yes
            [/status]
            side=$unit.side
            moves=1
            attacks_left=1
        [/modify_unit]

        [floating_text]
            x,y=$x2,$y2
            # po: short text, only displayed for a moment
            text="<span color='#ffc0cb'>" + _ "charm" + "</span>"
        [/floating_text]
    [/event]

    [event]
        name=side turn end, scenario end
        # Releasing the unit in the same turn has a few reasons:
        # - a charmed unit cannot be charmed again
        # - if the scenario ends, we can still correct the ownership
        # - things like healing by allies work the usual way
        first_time_only=no
        id=charm_release

        [store_unit]
            [filter]
                side=$side_number
                status=charmed
            [/filter]
            variable=charmed_units
        [/store_unit]

        [foreach]
            array=charmed_units
            [do]
                {VARIABLE this_item.side $this_item.variables.real_side}
                {CLEAR_VARIABLE this_item.variables.real_side}
                {CLEAR_VARIABLE this_item.status.charmed}
                [unstore_unit]
                    variable=this_item
                [/unstore_unit]
            [/do]
        [/foreach]

        {CLEAR_VARIABLE charmed_units}
    [/event]
#enddef

permanent

This version of the weapon special is a gamble. You can obtain the other unit for good, but you also risk losing this unit. When you lose this unit, the opponent controls a unit with charm. You might regain it when he uses this weapon special.

#define WEAPON_SPECIAL_CHARM
    # dummy weapon special used to describe the effect to the user and filter on special's id
    [dummy]
        id=weapon_charm
        name= _ "charm"
        description= _ "Turns a living level 1 or level 0 unit to your side. Beware, if all of your attacks miss, the charm user turns to the defender side, even if it is your leader. You can not charm an enemy leader or a non-living creature." 
        apply_to=opponent
        active_on=offense
    [/dummy]
#enddef

#define CHARMING_EVENTS
    # event that creates a "charm has worked" variable
    # and sets it to "yes" if the attacker hits at least once.
    [event]
        name=attacker_hits
        first_time_only=no
        id=charm_detect

        [filter_attack]
            special_id=weapon_charm
        [/filter_attack]
        [filter_second]
            canrecruit=no
            level=0,1
            [not]
                status=unplagueable
            [/not]
        [/filter_second]

        [modify_unit]
            [filter]
                id=$unit.id
            [/filter]
            [variables]
                charm_has_worked=yes
            [/variables]
        [/modify_unit]
    [/event]

    # Event that shifts a unit to the other side,
    # if the defending unit:
    #       - is lvl0 or lvl1
    #       - and is not a leader unit 
    #       - and is a not a "non-living" creature
    # Then:
    # -> if the attacker missed all attacks, it goes to the defender’s side.
    # -> if the attacker hit once at least, the defender goes to the attacker’s side.
    [event]
        name=attack_end
        first_time_only=no
        id=charm_convert

        [filter_attack]
            special_id=weapon_charm
        [/filter_attack]
        [filter_second]
            canrecruit=no
            level=0,1
            [not]
                status=unplagueable
            [/not]
        [/filter_second]

        [if]
            [variable]
                name=unit.variables.charm_has_worked
                boolean_equals=no
            [/variable]
            [then]
                {VARIABLE unit.side $second_unit.side}
                [unstore_unit]
                    variable=unit
                    text= _ "Charm failed!"
                    {COLOR_HARM}
                [/unstore_unit]
            [/then]
            [else]
                {VARIABLE second_unit.side $unit.side}
                [unstore_unit]
                    variable=second_unit
                    text= _ "Charmed!"
                    {COLOR_HEAL}
                [/unstore_unit]

                # The variable needs to be unset as well.
                {CLEAR_VARIABLE unit.variables.charm_has_worked}
                [unstore_unit]
                    variable=unit
                [/unstore_unit]
            [/else]
        [/if]
    [/event]
#enddef

Bloodlust

Bloodlust is a very simple ability. If a unit having bloodlust kills an enemy unit when attacking, it may attack again, provided that there are more enemy units adjacent to it.

This would give the bloodlust ability to all Dwarvish Ulfserkers (making them insanely powerful):

{BLOODLUST (type=Dwarvish Ulfserker)}

#define BLOODLUST FILTER
    [event]
        name=die
        first_time_only=no

        [filter_second]
            {FILTER}
        [/filter_second]

        [modify_unit]
            [filter]
                x,y=$x2,$y2
            [/filter]
            moves=0
            attacks_left=1
        [/modify_unit]
    [/event]
#enddef

Pickpocket

This special could also be called loot. When a unit with this attack special successfully hits an enemy unit, it gains a certain amount of gold.

To do this, use this code:

#define WEAPON_SPECIAL_PICKPOCKET
    # Canned definition of the pickpocket ability to be included in a
    # [specials] clause.
    # dummy weapon special used to describe the effect to the user
    # and filter on special's id
    [dummy]
        id=weapon_pickpocket
        name= _ "pickpocket"
        description= _ "Gain money for attacking your foe. Each strike scores you one gold."
        apply_to=opponent
        active_on=offense
    [/dummy]
[/specials]
[/attack]

    # event that creates a "pickpocket has worked" variable
    # and sets it to "yes" if the attacker hits at least once.
    [event]
        name=attacker_hits
        first_time_only=no
        [filter_attack]
            special_id=weapon_pickpocket
        [/filter_attack]
        [store_unit]
            [filter]
                x,y=$x1,$y1
            [/filter]
            variable=unit_att_with_pickpocket
            mode=append
        [/store_unit]
        [set_variable]
            name=unit_att_with_pickpocket.variables.pickpocket_has_worked
            value=yes
        [/set_variable]
        [unstore_unit]
            variable=unit_att_with_pickpocket
        [/unstore_unit]
        {CLEAR_VARIABLE unit_att_with_pickpocket}
    [/event]
    [event]
        name=attacker_hits
        first_time_only=no
        [filter_attack]
            special_id=weapon_pickpocket
        [/filter_attack]
        [store_unit]
            [filter]
                x,y=$x1,$y1
            [/filter]
            variable=pickpocketer
            mode=append
        [/store_unit]   
        [store_unit]
            [filter]
                x,y=$x2,$y2
            [/filter]
            variable=pickpocketed
            mode=append
        [/store_unit]
        [if]
            [variable]
                name=pickpocketer.variables.pickpocket_has_worked
                boolean_equals=yes
            [/variable]
            [then]
                [gold]
                    side=$side_number
                    amount=2
                [/gold]
                [unstore_unit]
                    variable=pickpocketed
                    text="!"
                    {COLOR_HEAL}
                [/unstore_unit]
            [/then]
        [/if]
        {CLEAR_VARIABLE pickpocketer,pickpocketed}
    [/event]
    [+attack]
    [+specials]
#enddef

It can be placed after the [unit_type] tag, or in its own .cfg file.

To change the amount of gold given per hit, change

[gold]
    side=$side_number
    amount=X
[/gold]

Where X is the amount of gold you want.

If you want the gold to be constant, given at the end of the turn if at least one of the attack hits, instead of X amount of gold per hit, change

[event]
    name=attacker_hits
    first_time_only=no

to

[event]
   name=attack_end
   first_time_only=no

Soultaker

Any unit with this will gain an additional point of damage per strike every time it kills an enemy. Made for Melon’s Youkai faction (https://r.wesnoth.org/t20100). A variant which uses this as weapon special is used in ageless era (https://r.wesnoth.org/t25274).

One can add this as ability or as weapon special. As ability it will be used when the other unit is killed by any attack of this unit. Using it as weapon special is similar to the Necromancer’s plague staff: It will only take effect when the attack with the special is used to land the killing blow.

Place the following in any .cfg file loaded by the campaign or era:

#define SOULTAKER_DUMMY
   [dummy]
       id=soultaker
       name= _ "soultaker"
       description=_ "This unit gains an additional point added to its melee damage whenever it kills a living unit."
   [/dummy]
#enddef

#define SOULTAKER_EVENT
    [event]
        name=die
        first_time_only=no
        id=soultaker

        [filter]
            [not]
                status=undrainable
            [/not]
        [/filter]

        # Use this check if you want to use Soultaker as ability.
        [filter_second]
            ability=soultaker
        [/filter_second]

        # To use Soultaker as weapon special, use this check INSTEAD of the above one.
        # [filter_second_attack]
        #     special_id=soultaker
        # [/filter_second_attack]

        [floating_text]
            x,y=$x2,$y2
            text="<span color='#00ff00'>" + _ "+1 damage" + "</span>"
        [/floating_text]

        [object]
            silent=yes
            duration=forever
            [filter]
                x,y=$x2,$y2
            [/filter]

            [effect]
                apply_to=attack
                increase_damage=1
                range=melee
                # This will increase all melee attacks by 1. To only increase the attack used in this fight, use
                # name=$second_weapon.name
            [/effect]
        [/object]
    [/event]
#enddef

And the following in the unit's [abilities] tag. If you changed the code to use the weapon special variant, add instead to the unit’s [attack] an [specials] tag, into which you place:

{SOULTAKER_DUMMY}

Add to the [campaign] or [era] tag:

{SOULTAKER_EVENT}

Works

Unit with ability works will produce 1 gold per turn. This mechanism is used in the mainline multiplayer map »A New Land«.

Put this macro into you code before the last piece of code.

#define ABILITY_WORKS
    [works]
        id=peasant_works
        name="works"
        description= _ "This unit produces 1 gold per turn."
    [/works]
#enddef

Put this event into your code.

[event]
    name=side turn
    first_time_only=no
    [store_unit]
        [filter]
            ability=peasant_works
            side=$side_number
        [/filter]
        variable=workers
    [/store_unit]

    [foreach]
        array=workers
        [do]
            [gold]
                side=$this_item.side 
                amount=1
            [/gold] 
            [floating_text]
                x,y=$this_item.x,$this_item.y
                text="<span color='#ffff00'>" + _ "+1 gold" + "</span>"
            [/floating_text]
        [/do]
    [/foreach]

    {CLEAR_VARIABLE workers}
[/event]

And give the unit the ability like this:

[object]
    silent=yes
    [effect]
        apply_to=new_ability
        [abilities]
            {ABILITY_WORKS}
        [/abilities]
     [/effect]
 [/object]

Mind Flay

The weapon special gives an attacker 1 point of exp taken from a defender for each hit. This will violate minimum experience (i.e. defender can go below 0).

Give this special to the attack(s) you want it to have:

#define WEAPON_SPECIAL_MIND_FLAY
    [mindflay]
        id=mind_flay
        name= _ "Mind Flay"
        description= _ "When used offensively, each hit of the mind flay attack takes 1 point of experience from the defender and gives it to the attacker."
        active_on=offense
    [/mindflay]
#enddef

Include these events into your scenario:

[event]
    name=attack
    first_time_only=no
    [filter_attack]
        special_id=mind_flay
    [/filter_attack]
    {VARIABLE hit_number 0}
[/event]
[event]
    name=attacker_hits
    first_time_only=no
    [filter_attack]
        special_id=mind_flay
    [/filter_attack]
    {VARIABLE_OP hit_number add 1}
[/event]
[event]
    name=attack_end
    first_time_only=no
    [filter_attack]
        special_id=mind_flay
    [/filter_attack]
    {VARIABLE_OP second_unit.experience sub $hit_number}
    {VARIABLE_OP unit.experience add $hit_number}
    [unstore_unit]
        variable=unit
        text=$hit_number
        blue=255
    [/unstore_unit]
    [unstore_unit]
        variable=second_unit
    [/unstore_unit]
    {CLEAR_VARIABLE hit_number}
[/event]

Initiative

Initiative is an aura ability. Much like leadership, it affects adjacent allies but not the unit itself.

The ability is used in HttT by Li’sar, you can copy the code from data/campaigns/Heir_To_The_Throne/utils/abilities.cfg

Blitz

UtBS and TroW have with distract an ability, which lets adjacent units ignore the ZoC. It works similar to leadership and initiative, the bonus is valid while the unit is adjacent.

This ability does the same, but it works similar to healing: The bonus is applied at the beginning of the turn and still valid when not anymore being adjacent.

But it also differs from the way healing works for allied units:

• With healing, it is useful if you move your injured unit to an ally, so that it is adjacent at the healing time.
• With this ability, the unit who wants the bonus must be adjacent at the start of his own turn.

#define ABILITY_BLITZ
    [dummy]
        id=blitz    
        name= _ "blitz"
        description= _ "Allies that start their turn adjacent to this unit are granted skirmisher for that turn."
        special_note= _ "Instead of healing other units, this unit grants temporarily skirmisher for allied units at the beginning of their turn."
        active_on=offense
        affect_self=no
        affect_allies=yes
        [affect_adjacent][/affect_adjacent]
    [/dummy]
#enddef

#define ABILITY_BLITZ_EVENT
    [event]
        name=side turn
        first_time_only=no

        [modify_unit]
            # The units adjacent to a unit with the blitz ability …
            [filter]
                side=$side_number
                [filter_adjacent]
                    is_enemy=no
                    ability=blitz
                [/filter_adjacent]
            [/filter]

            # … receive temporarily this ability.
            [object]
                duration=turn end
                [effect]
                    apply_to=new_ability
                    [abilities]
                        {ABILITY_SKIRMISHER}
                    [/abilities]
                [/effect]
            [/object]
        [/modify_unit]
    [/event]
#enddef

Immune to drain or plague or poison

To make a unit immune to plague, poison or/and draining of life force, set the right [status] for this unit: One or multiple of unpoisonable, undrainable, unplagueable.

There are many ways to change a status, it can be set directly with [modify_unit], at recruitment via a [trait], or by giving the unit an [object]. In mainline, a [trait] is used to make undead units immune. Traits also have a name and description, which can be used to make it visible to the player that this unit is immune.

#define TRAIT_UNDRAINABLE
    # We make vampires undrainable with a trait.
    # Traits show up in the help browser, thus they should have proper descriptions.
    [trait]
        id=undrainable
        availability=musthave
        male_name= _ "vampire"
        female_name= _ "female^vampire"
        description= _ "This unit’s life force cannot be drained."
        help_text= _ "Vampires are like Undead immune to drain and plague, but still susceptible to poison. While this trait is usually seen among vampire units, other mythical beings have also been seen with it. Even some Mages managed to acquire it."
        # vampire is not a good name for a trait, as you can give the trait to anybody
        [effect]
            apply_to=status
            add=undrainable
        [/effect]
        [effect]
            apply_to=status
            add=unplagueable
        [/effect]
    [/trait]
#enddef

When you define a new [unit_type], add to it:

{TRAIT_UNDRAINABLE}
num_traits=3 # if you still want it to get 2 other traits

In other cases, if you want to make unit immune, i.e. one from mainline, give it the trait another way:

[event]
    name=prerecruit
    first_time_only=no
    [filter]
        type_adv_tree=Mage
        [or]
            race=elf
            side=2
        [/or]
    [/filter]

    [modify_unit]
        [filter]
            id=$unit.id
        [/filter]
        {TRAIT_UNDRAINABLE}

        # Or without trait / object:
        # [status]
        #     undrainable=yes
        # [/status]
    [/modify_unit]
[/event]

Whirlwind Attack

This attack is supposed to be an attack when you spin with your weapons in arms, hitting all nearby enemies, while they cannot counter. It should be used with the magical weapon special, because the spinning weapons are not easy to dodge and the player would pick to attack the unit with the lowest defence without it. It works with drain, slow and poison weapon specials. The attack is supposed to be attack-only, but it can be easily edited to work also on defence.

This is a pair of two macros, one is a weapon special that makes the enemy unable to counter (lowers the number of attacks by 10; for the case if there was a boss or something). The other one is an event that damages the units, that should be placed into every scenario where the unit appears (or the era), preferably through a macro.

This is the part that is the weapon special that marks it:

[attacks]      #This can be changed to a dummy tag if you don't want it to do anything.
    id=whirlwind
    name= _ "whirlwind"
    description= _ "When this attack is used, all units adjacent the attacker take the damage, and cannot be countered."
    value=0
    apply_to=opponent
    active_on=offense
[/attacks]

This is the event:

 [event]
    name=attacker_hits
    first_time_only=no
    [filter_attack]
        special_id=whirlwind
    [/filter_attack]
    {VARIABLE has_drain no}      # Notifies the weapon specials
    {VARIABLE has_slow no}
    {VARIABLE has_poison no}
    [if]
        [variable]
            name=weapon.specials.drains.id
            equals=drains
        [/variable]
        [then]
            {VARIABLE has_drain yes}
        [/then]
    [/if]
    [if]
        [variable]
            name=weapon.specials.poison.id
            equals=poison
        [/variable]
        [then]
            {VARIABLE has_poison yes}
        [/then]
    [/if]
    [if]
        [variable]
            name=weapon.specials.slow.id
            equals=slow
        [/variable]
        [then]
            {VARIABLE has_slow yes}
        [/then]
    [/if]
    [if]
        [variable]
            name=has_drain
            boolean_equals=yes
        [/variable]
        [then]
            [store_unit]        #We need to know how many units were drained, and what were their resistances
                [filter]
                    [filter_adjacent]
                        x,y=$x1,$y1
                    [/filter_adjacent]
                    [not]
                        side=$unit.side
                    [/not]
                    [not]         #The target unit is already hit by the attack
                        x,y=$x2,$y2
                    [/not]
                    [not]
                        status=undrainable,petrified
                    [/not]
                [/filter]
                variable=units
            [/store_unit]
            {VARIABLE healed_amount 0}
            [foreach]
                array=units
                [do]
                    [switch]            #Check the resistances
                        variable=weapon.type
                        [case]
                            value=arcane
                            {VARIABLE_OP healed_amount add "$($this_item.resistance.arcane*$weapon.damage)"}
                        [/case]
                        [case]
                            value=fire
                            {VARIABLE_OP healed_amount add "$($this_item.resistance.fire*$weapon.damage)"}
                        [/case]
                        [case]
                            value=cold
                            {VARIABLE_OP healed_amount add "$($this_item.resistance.cold*$weapon.damage)"}
                        [/case]
                        [case]
                            value=blade
                            {VARIABLE_OP healed_amount add "$($this_item.resistance.blade*$weapon.damage)"}
                        [/case]
                        [case]
                            value=pierce
                            {VARIABLE_OP healed_amount add "$($this_item.resistance.pierce*$weapon.damage)"}
                        [/case]
                        [case]
                            value=impact
                            {VARIABLE_OP healed_amount add "$($this_item.resistance.impact*$weapon.damage)"}
                        [/case]
                    [/switch]
                [/do]
            [/foreach]
            #Float the healed amount over the unit, like if it had drained
            [floating_text]        #Two numbers will float, the one from the regular hit and one from this
                x,y=$x1,$y1        #Operating with huge numbers because rounding is a problem
                text="<span color='#00ff00'>" + "$($healed_amount/200)" + "</span>"
            [/floating_text]
            [heal_unit]
                [filter]
                    x,y=$x1,$y1
                [/filter]
                amount=$($healed_amount/200)
                restore_statuses=no
                animate=no
            [/heal_unit]
            {CLEAR_VARIABLE units,healed_amount}
        [/then]
    [/if]
    [harm_unit]
        [filter]
            [filter_adjacent]
                x,y=$x1,$y1
            [/filter_adjacent]
            [not]
                side=$unit.side
            [/not]
            [not]
                x,y=$x2,$y2
            [/not]
            [not]
                status=petrified
            [/not]
        [/filter]
        [filter_second]
            x,y=$x1,$y1
        [/filter_second]
        amount=$weapon.damage
        damage_type=$weapon.type
        fire_event=yes
        experience=yes      #You will have to think about this
        poisoned=$has_poison   #We have detected these two effects before
        slowed=$has_slow
    [/harm_unit] 
    {CLEAR_VARIABLE has_slow,has_poison,has_drain}
 [/event]

See Also

• UsefulWMLFragments
• ReferenceWML