Add IWD's "Evasion" ability to BGEE/BG2EE
Author: Duns Scotus, the SubtleDoctor
Version 3.4
WHAT THIS IS
This is a drop-in utility that lets anyone add the IWD "Evasion" feat to their BGEE or BG2EE game. A character with this feat, when targeted by certain magic spells, can make a saving throw vs. Breath Weapon to avoid the effect altogether. The spell only works on them if the character fails that save... and then the spell itself may offer its own normal saving throw to avoid or reduce the effect (e.g. Fireball).
The way this works is, it patches a spell - let's say Fireball - with a 177 effect calling an .EFF file before the rest of the spell's effects take place. The .EFF is created by this function, with an opcode 318 effect protecting the target against the effects of Fireball, IF the target has the Evasion spellstate. Then the function creates another 318 effect in Fireball, before the 177 effect. This 318 effect protects against that .EFF... but only if the target fails a saving throw.
So the spell has an effect making targets with the Evasion state immune to it, but those targets must make a saving throw for their immunity to be effective. The functional result is exactly like IWD's Evasion: you get an extra saving throw to avoid the effects of a spell.
This version is more generalized, and thus a lot more versatile, than the actual version of Evasion in IWDEE. This one can use any arbitrary spellstate, not just the Evasion spellstate; and it can use whichever saving throw you like; and you can apply different variants of the Evasion effect however and however much you like. So you can let thieves evade fireballs, and berserkers evade charms, and you can switch the "Shield" spell to give an extra save to avoid Magic Missiles, instead of full immunity, etc. This besically can be used to give anybody an extra saving throw or % chance to avoid any spells or spell effects.
HOW TO USE THIS
If you don't already have one, make a folder called "lib" in your mod's main folder. Drop the "spell_evasion" .tpa file there. Unless you want to edit the function itself, the placement of this folder is quite strict.
Now you need to do four things:
1) Activate the Evasion function with the following code:
2) Create a spell or other effect that sets the Evasion spellstate for some character. NOTE: this does not have to be the actual Evasion spellstate (252)... you can add a new spellstate and use that one. This allows you to use the basic "extra chance to save" mechanic in different ways, against different spells, with different saving throws, for different characters. See below for more information.
For example, I create a spell to grant the Evasion ability permanently like this:
COPY_EXISTING ~spcl221.spl~ ~override/d5evade.spl~
SAY NAME1 ~ ~
SAY UNIDENTIFIED_DESC ~ ~
LPF DELETE_EFFECT END
LPF ADD_SPELL_EFFECT INT_VAR opcode = 328 target = 1 parameter2 = 252 timing = 9 special = 1 END
BUT_ONLY
END
3) Apply the Evasion passive ability to some character. You can add it to a kit ability table, or make it an HLA, or make it a temporary effect of a custom spell... you can apply it directly to .CRE files... whatever you want. You just need to apply that 328 effect to set the Evasion spellstate to someone.
4) Apply the Evasion behavior to some spells:
LAF add_evade_spell
INT_VAR
evasion_spellstate = 252
evasion_save = 2
STR_VAR
evade_ext = ~spl~
evade_res = EVAL ~%spell%~
evade_prefix = ~[up to 4-character string]~
RET
evasion_ind
END
There are some things there that need explaining.
The "evasion_spellstate" variable refers to an entry in SPELLSTATE.IDS. For traditional IWD-style Evasion, I use the Evasion spellstate, #252. But you can use any other spellstate in your application, including custom spellstates.
The "evasion_save" variable refers to the saving throw used for the extra save. The traditional Evasion saving throw is vs. Breath Weapon (something like a Dodge save, I think). But you can apply an alternate version that uses other saves... you can give characters an extra Death save to avoid Energy Drain spells, or something like that.
The "evade_ext" variable refers to the extension of the file that should be subject to evasion. When patching spells use ~spl~ and when patching items use ~itm~.
The "evade_res" variable refers to the spell (or item!) being patched by the function. To apply this to one spell (or item), simply use that spell (or item)'s name. If applying it to a list of spells (or... eh, you get the point), as in the example above, use the variable to represent the list.
The "evade_prefix" variable must be created by you. It should be unique, and it MUST be 4 characters or fewer, and it should not conflict with any spell or item name when any 3 numbers are appended to it. I use "d5ev" - "d5" is my modding prefix, and "ev" is for evasion. This prefix has two uses: 1) it is combined with the "evasion_ind" integer variable to create a unique filename for the .EFF files uses with each spell to which this function is applied; and 2) it is combined with the number of the spellstate used, to create a .2DA file which lists all of the spells and the associated .EFF files to which this function is applied. The function checks this .2DA file to prevent the same evasion check from being applied more than once.
Note: DO NOT use the same 4-letter prefix with different versions of this that use different spellstates. It could cause problems.
This package has a pre-defined array containing the base set of spells that can be evaded in IWD. You can call this array with:
LAF add_evade_spell INT_VAR evasion_spellstate = 252 evasion_save = 2 STR_VAR evade_ext = ~spl~ evade_res = EVAL ~%evadable_spell%~ evade_prefix = ~[prefix]~ END
END
LAF add_evade_spell INT_VAR evasion_spellstate = 252 evasion_save = 2 STR_VAR evade_ext = ~itm~ evade_res = EVAL ~%evadable_spell%~ evade_prefix = ~[prefix]~ END
END
NEW IN VERSION 3
I've been working to make the function even more flexible. Here are the function's variables:
- INT_VAR evasion_spellstate = [row number of SPLSTATE.IDS]
- INT_VAR evasion_class = [number from 1st column of CLASS.IDS]
- INT_VAR evasion_kit = [hexadecimal number from 1st column of KIT.IDS]
- INT_VAR evasion_save = [0, 1, 2, 4, 8, or 16]
- INT_VAR evasion_chance = [number from 1 to 100]
- STR_VAR evade_condition = ~[spellstate]/[class]/[kit]~
- STR_VAR evade_ext = [~spl~ or ~itm~]
- STR_VAR evade_res = [EVAL] ~[spell or item, or variable from list of spells/items]~
- STR_VAR evade_prefix = ~[up to 4-character alphanumeric string that you create]~
The function should work with either spells or items, or both. Once you have your list of spells and/or items you want to be evadable, you can decide whether the group of people who can evade them will be defined by having a spellstate set, or being in a certain class, or having in a certain kit. I described above how to make spells evadable by thieves with spellstate 252; now in Might & Guile, I am also using this to allow Rangers an extra saving throw vs. Death/Poison to avoid disease and poison effects. After I collect the list of spells and items I want to be resistible, I run the function like so:
ACTION_PHP_EACH poison_disease_spells AS resisted_effect => ind BEGIN
LAF add_evade_spell INT_VAR evasion_class = 12 evasion_save = 4 STR_VAR evade_ext = ~spl~ evade_condition = ~class~ evade_res = EVAL ~%resisted_effect%~ evade_prefix = ~D5RR~ END
END
This makes it quite simple, there is no need to create a new spellstate, no need to add anything to kit ability tables or to patch .CRE files. The evasion effect will now work automatically for anyone in the ranger class - including enemy NPCs!
New in 3.1, you can set the %evasion_chance% variable to an integer between 1 and 100. This will make you less likely to evade the effect; in conjunction with a saving throw, it means you wil have to make your save and be within the percent chance to evade. Alternatively, you can set %evasion_save% to zero, in which case the function will operate entirely according to the percent chance roll. In this way, it will work exactly like Magic Resistance, but targeted for the specific set of spells/items that you list. (You still need to define an evasion condition - spellstate, class, or kit - to determine who gets this selective MR.)
Compatibility
BG2 already has a High-Level Ability called "Evasion," so for the sake of clarity I have taken to calling this ability "Spell Evasion." But this function itself doesn't add any strings; all you see in-game is "Charname: save vs. breath weapon" and the spell will be evaded.
Note: this will only work in the EE versions of the game, version 1.4 or higher.