Harmonious Conversion Fist: The Methodology
Originally posted by me to RPGNet, here transcribed for record-keeping purposes. This is a rough guideline, which takes into account the most basic difficulties of conversion.
In general, unless your custom Charm is meant for use with combat or social combat conversion is pretty easy. You just need to add appropriate tags, and tags are mostly self-explanatory -- if the Charm creates a huge signature, it's Obvious, if it does bad things to demons and undead, it's Holy, etc. If you wrote any sorcery or necromancy, conversion is effortless unless the spell interacts with the combat rules.
Combat Charms have a few areas where the rules-changes are harder, namely Extra Action Charms, defensive Charms and simple Charms meant for combat use. I deal with them like this:
--Extra Action Charms create a "magical flurry" that allows you to take a Flurry with no die penalties, a Speed cost equal to the highest Speed in the flurry and a DV reduction equal to the highest DV reduction in the flurry. A special case of this are Independent Action Charms (such as Charcoal March of Spiders Form.) While there's no precedent yet, I suspect that charms that gave you independent actions will allow you to make a magic flurry as above, except that you're allowed to use a number of Charms equal to the number of actions in the flurry, with no one action benefiting from more than one non-reflexive Charm.
--Persistent defenses and reflexive defenses work by analogy to the corebook. Either type can change the Ability or Attribute that calculates your DV while they are active. (For example, if you had the Sun's Invulnerable Smile Charm, which gives you a reflexive Charisma + Performance dodge, the Second Edition version of that Charm would allow you to calculate your Dodge DV using your Charisma + Performance + Essence, ignoring all penalties, against one attack.)
--Charms and spells that increase the difficulty to hit you or subtract successes from your opponent's attack roll increase your DV (both parry and dodge) by the amount that they would have subtracted from rolls or added to the to-hit difficulty. Charms and spells that reduce your opponent's attack die pools or add to your defensive die pools increase your DV by half the change in die pool.
--Simple Charms meant for combat use generally have Speed 4, DV -1, rather than the default Speed 6, DV -1. There are exceptions to this rule, so it's a judgement call, but generally a Charm meant to replace an attack has the same Speed and DV penalty as an attack.
--Charms that had a duration of one turn now have a duration of one action.
--Charms that have an effect outside the normal parameters of damage have the Crippling tag. As long as your Charm is reflexive or of instant duration, it will probably have the Combo-OK tag; otherwise, it probably has the Combo-Basic tag. (I'm not entirely sure on this last point, mind.) Permanent Charms don't Combo at all.
Now for the fun bit: social combat.
Charms that affect a target's mind, emotions or beliefs are resisted with the target's MDV. Remove any resistance rolls allowed to the target or any difficulty based on the target's traits. If the Charm previously worked without requiring a roll, such as the Alchemica Charm Pattern Facilitation Module, MDV replaces any of the defender's traits that are mentioned. (It's now difficult to have a "two-tiered" effect that allows targets to partially resist; I'd do it by halving the target's MDV against the Charm, then having an additional effect for doubling the new MDV.) You may wish to make the Charm undodgeable or unparryable, depending on whether or not you think it can be argued against or ignored. (Charms that were resisted with Willpower in First Edition are often unparryable.) Charms almost always count as unnatural mental influence (see p. 181).
Look at Page 179, and decide which tag(s) best suit your Charm -- Emotion if the Charm instills an emotion, Illusion if it instills a belief, etc. If you want the Charm to be useful in physical combat, don't use the Social tag, which shifts the Speed cost of the Charm to long ticks.* Tags matter more in social combat than in physical combat because a number of defensive social Charms work only against certain types of effect.
Charms that ensure long-term loyalty do so by forming a new Intimacy, or upgrading an Intimacy to an additional Motivation (or, for high-Essence Charms, both.) Similarly, defensive Charms that perfectly defeat attempts to persuade often do so by forming a new Intimacy or upgrading an existing one.
If your Charm allowed you to control a target's actions completely (far more common with spells than Charms), it is a Total Control effect. If it permitted you to command a target to commit suicide or otherwise completely betray himself, you must note in the description that it allows Unacceptable Orders. (For example, the spell Threefold Binding of the Heart does both -- it is a Total Control effect which establishes a new Motivation for the target -- serve the caster of this spell -- and allows the caster to give the target Unacceptable Orders.)
Charms that provide a die bonus to resist persuasion are Integrity Charms, and provide a bonus to MDV equal to half the die bonus they granted in First edition. Similarly, all Charms that allow an Exalt to resist persuasion are Integrity Charms. Most other Charms fall under the same ability as they did in First Edition.
In general, unless your custom Charm is meant for use with combat or social combat conversion is pretty easy. You just need to add appropriate tags, and tags are mostly self-explanatory -- if the Charm creates a huge signature, it's Obvious, if it does bad things to demons and undead, it's Holy, etc. If you wrote any sorcery or necromancy, conversion is effortless unless the spell interacts with the combat rules.
Combat Charms have a few areas where the rules-changes are harder, namely Extra Action Charms, defensive Charms and simple Charms meant for combat use. I deal with them like this:
--Extra Action Charms create a "magical flurry" that allows you to take a Flurry with no die penalties, a Speed cost equal to the highest Speed in the flurry and a DV reduction equal to the highest DV reduction in the flurry. A special case of this are Independent Action Charms (such as Charcoal March of Spiders Form.) While there's no precedent yet, I suspect that charms that gave you independent actions will allow you to make a magic flurry as above, except that you're allowed to use a number of Charms equal to the number of actions in the flurry, with no one action benefiting from more than one non-reflexive Charm.
--Persistent defenses and reflexive defenses work by analogy to the corebook. Either type can change the Ability or Attribute that calculates your DV while they are active. (For example, if you had the Sun's Invulnerable Smile Charm, which gives you a reflexive Charisma + Performance dodge, the Second Edition version of that Charm would allow you to calculate your Dodge DV using your Charisma + Performance + Essence, ignoring all penalties, against one attack.)
--Charms and spells that increase the difficulty to hit you or subtract successes from your opponent's attack roll increase your DV (both parry and dodge) by the amount that they would have subtracted from rolls or added to the to-hit difficulty. Charms and spells that reduce your opponent's attack die pools or add to your defensive die pools increase your DV by half the change in die pool.
--Simple Charms meant for combat use generally have Speed 4, DV -1, rather than the default Speed 6, DV -1. There are exceptions to this rule, so it's a judgement call, but generally a Charm meant to replace an attack has the same Speed and DV penalty as an attack.
--Charms that had a duration of one turn now have a duration of one action.
--Charms that have an effect outside the normal parameters of damage have the Crippling tag. As long as your Charm is reflexive or of instant duration, it will probably have the Combo-OK tag; otherwise, it probably has the Combo-Basic tag. (I'm not entirely sure on this last point, mind.) Permanent Charms don't Combo at all.
Now for the fun bit: social combat.
Charms that affect a target's mind, emotions or beliefs are resisted with the target's MDV. Remove any resistance rolls allowed to the target or any difficulty based on the target's traits. If the Charm previously worked without requiring a roll, such as the Alchemica Charm Pattern Facilitation Module, MDV replaces any of the defender's traits that are mentioned. (It's now difficult to have a "two-tiered" effect that allows targets to partially resist; I'd do it by halving the target's MDV against the Charm, then having an additional effect for doubling the new MDV.) You may wish to make the Charm undodgeable or unparryable, depending on whether or not you think it can be argued against or ignored. (Charms that were resisted with Willpower in First Edition are often unparryable.) Charms almost always count as unnatural mental influence (see p. 181).
Look at Page 179, and decide which tag(s) best suit your Charm -- Emotion if the Charm instills an emotion, Illusion if it instills a belief, etc. If you want the Charm to be useful in physical combat, don't use the Social tag, which shifts the Speed cost of the Charm to long ticks.* Tags matter more in social combat than in physical combat because a number of defensive social Charms work only against certain types of effect.
Charms that ensure long-term loyalty do so by forming a new Intimacy, or upgrading an Intimacy to an additional Motivation (or, for high-Essence Charms, both.) Similarly, defensive Charms that perfectly defeat attempts to persuade often do so by forming a new Intimacy or upgrading an existing one.
If your Charm allowed you to control a target's actions completely (far more common with spells than Charms), it is a Total Control effect. If it permitted you to command a target to commit suicide or otherwise completely betray himself, you must note in the description that it allows Unacceptable Orders. (For example, the spell Threefold Binding of the Heart does both -- it is a Total Control effect which establishes a new Motivation for the target -- serve the caster of this spell -- and allows the caster to give the target Unacceptable Orders.)
Charms that provide a die bonus to resist persuasion are Integrity Charms, and provide a bonus to MDV equal to half the die bonus they granted in First edition. Similarly, all Charms that allow an Exalt to resist persuasion are Integrity Charms. Most other Charms fall under the same ability as they did in First Edition.