"Alert" unit immune to backstab

[Helmet]

I need a Saurian Ambusher named Smekk to be immune to backstab. I thought I should make a trait called "alert" to bestow an immunity to backstab...but is such a thing even possible? Or do I need an event? An ability?

How would you code it? By the way, it's just one scenario and one unit, so the solution needn't be versatile.

The trait:

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#define TRAIT_ALERT
	[trait]
		id=alert
        	male_name= _ "alert"
        	female_name= _ "female^alert"	
        	description="Immune to backstab"
        	[effect]
        		apply_to=status
        		add=unbackstabbable #    I know there's no such thing     		       
        	[/effect]      
    	[/trait]
#enddef

The event:

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[event]
	name=attack
	first_time_only=no
		[filter_attack]
			special=backstab
		[/filter_attack]
		[filter_second]
			ability=alert
		[/filter_second]
		[modify_unit]
			[filter]
				id=Smekk
			[/filter]       
			???
		[/modify_unit]
[/event]

[beetlenaut]

I think this is a case where you have to give an object to all the OTHER units in the scenario that modifies their ability when your alert unit is involved. (Use a "unit placed" event.)

[Helmet]

I think this is a case where you have to give an object to all the OTHER units in the scenario that modifies their ability when your alert unit is involved. (Use a "unit placed" event.)

All the units with backstab must be recruited or recalled to appear on the map, so unit_placed seems promising.

I'm not sure how to modify backstab to exclude Smekk, though.

So...there's no way to filter attacks against Smekk? Something like...

Code: Select all

name=attack
[filter]
	id=Smekk
[/filter]
[if]
 ?

[WhiteWolf]

The way to do this is to create your own backstab ability that excludes Smekk, and then replace every backstab ability in the game with that one.

Insert the not-Smekk condition to backstab:

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#define WEAPON_SPECIAL_BACKSTAB_CUSTOM
    # Canned definition of the Backstab ability to be included in a
    # [specials] clause.
    [damage]
        id=backstab
        name= _ "backstab"
        description= _ "When used offensively, this attack deals double damage if there is an enemy of the target on the opposite side of the target, and that unit is not incapacitated (turned to stone or otherwise paralyzed)."
        multiply=2
        active_on=offense
        [filter_opponent]
            formula="
                enemy_of(self, flanker) and not flanker.petrified
            where
                flanker = unit_at(direction_from(loc, other.facing))
            "
            # ADDED LINES:
            [not]
                id=Smekk
            [/not]
            # ADDED end
        [/filter_opponent]
    [/damage]
#enddef

And to make the switch for this everywhere:

Code: Select all

# event in some toplevel place so it gets included to every scenario

[event]
    name=unit placed
    id=backstab_switcher
    first_time_only=no
    [filter]
        [has_attack]
            special=backstab
            # if you're on 1.15.x (idk which), it's 'special_id' and not 'special'
        [/has_attack]
    [/filter]
    
    [object]
        id=backstab_customizer
        [filter]
            id=$unit.id
        [/filter]
        [effect]
            apply_to=attack
            special(_id)=backstab
            
            remove_specials=backstab
            [set_specials]
                mode=append
                {WEAPON_SPECIAL_BACKSTAB_CUSTOM}
            [/set_specials]
        [/effect]
    [/object]
[/event]

EDIT:
And if you want to make it general with the 'Alert' ability, then make a [dummy] Alert ability, and in your modified backstab ability, use ability=alert_dummy instead of id=Smekk.

[Helmet]

Thanks, WhiteWolf! I tested the code with recruited units and it works some of the time, but most of the time the units can still backstab. I'm not 100% sure what the pattern is. Preliminary tests indicate that a unit may not backstab when it counter-attacks, and may not backstab when it's already in position for a backstab and doesn't need to move. But if a unit moves into position for a backstab, the backstab usually works.

At least the code works some of the time, which is great. That means the solution works; it just needs a little refining.

I'm on 1.15.7, so I used special_id=backstab.

The units with backstab are custom units, but I don't think that would cause a problem. They're nothing unusual, apart from backstab.

As Smekk only appears in scenario 3, I only put the event in scenario 3, just after start.

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[scenario]
	[prestart]
	[/prestart]
	[start]
	[/start]
	>>>			YOUR CODE HERE
[/scenario]

[WhiteWolf]

Backstab only works on offense, so counter-attacking units don't get backstab even from the vanilla special. So it sounds like it doesn't work at all.
I'm not sure if it's the source of all the problems, but I did make a mistake, the id of the modified backstab special should be unique.

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#define WEAPON_SPECIAL_BACKSTAB_CUSTOM
    # Canned definition of the Backstab ability to be included in a
    # [specials] clause.
    [damage]
        id=backstab # problem here -> rename to backstab_custom or sth like that
...

Could try fixing this first.
You could also open the inspection window for a recruited unit and check that the object has been correctly applied (or not...?). I'm just guessing now, but maybe I can test the thing tomorrow.

[Helmet]

That didn't work completely...but progress was made. Now (it seems) the first unit recruited gets the object, and the rest don't. So it seems to work for one unit. Hmm.

[beetlenaut]

Now (it seems) the first unit recruited gets the object, and the rest don't.

By default, an object with a defined ID can only be picked up once per scenario, even if it is removed later or first_time_only=no is set for the event. You can remove this restriction by setting take_only_once=no.

[Helmet]

That did it! Thanks!

[Celtic_Minstrel]

EDIT:
And if you want to make it general with the 'Alert' ability, then make a [dummy] Alert ability, and in your modified backstab ability, use ability=alert_dummy instead of id=Smekk.

Personally I prefer to use my own tag for custom abilities, rather than [dummy]. You can use any tag as an ability, and if it's not an ability recognized by the engine, it will just have no effect other than showing in the sidebar.

[WhiteWolf]

You can use any tag as an ability, and if it's not an ability recognized by the engine, it will just have no effect other than showing in the sidebar.

Hmm, I'm aware of that, but is there any advantage to actually doing that? My reason for not doing so is that the id identifies everything anyway, and by using [dummy] for everything, when I just open up old code, and see [dummy], I immediately know - yes, this is an event-implemented ability. If I called it its name, I'd have to think for an extra second if it's an engine-supported tag or a custom name.

[Celtic_Minstrel]

There can be advantages. When filtering, you can reference an ability either by tag or by ID. For example, if you had a group of related abilities, you could give them the same tag but a different ID.

I guess that probably doesn't apply to this specific case, but it's something to be aware of, at least.

[newfrenchy83]

if you use 1.15.7 then you could make an alert abilities without customi backstab

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#define ABILITY_SPECIAL_ALERT
    #  to be included in a [abilities] clause.
    [damage]
        id=alert
        name= _ "alert"
        female_name= _ "female^alert"
        description= _ "Immune to backstab"
        divide=2
        cumulative=no
        active_on=defense
        apply_to=opponent
        affect_self=yes
        [filter_opponent]
            [filter_weapon]
                special_id_active=backstab
            [/filter_weapon]
        [/filter_opponent]
    [/damage]
#enddef

the divide by 2 applied to opponent cancel the multiply=2 of backstab without use a customised backstab or [event]

[Helmet]

if you use 1.15.7 then you could make an alert abilities without customi backstab...

A brand new feature? Cool! I'm using 1.15.8 because I like brand new features. Thank you.

Early on, I had tried to think of a way to counteract the doubling of damage through division, but my limited knowledge of WML didn't allow me progress the idea beyond the conceptual stage.

[Helmet]

if you use 1.15.7 then you could make an alert abilities without customi backstab...
the divide by 2 applied to opponent cancel the multiply=2 of backstab without use a customised backstab or [event]

The code works great...except for one tiny little thing.

In the Attack Enemy window, the word "backstab" is not grayed-out when a unit that can backstab tries to backstab an Alert unit. Yes, the damage displayed remains the normal damage, and the Alert unit only takes normal damage, but since "backstab" is not grayed-out, a player might assume damage will be doubled anyway.

Is there a way to gray-out the word backstab in the Attack Enemy window?

I'm thinking...no. The way the Alert ability works is to permit the damage to be doubled, then divide it in half. So...in a sense, a unit is still being backstabbed, but for half damage. Nonetheless, I thought I should ask.

Thanks.