Diplomancing the Stone, Part 5

Side note: for the benefit of anyone wondering, who may not be of that certain age to immediately get the reference, "Diplomancing the Stone" is a nod to the 1984 action / romance yarn "Romancing the Stone" starring Kathleen Turner and Michael Douglas.

Persuasion

So far we have dealt with determination of initial NPC attitudes, and use of the Diplomacy skill to influence this Diplomatic Attitude.  We also looked at an optional mechanic to quantify non-platonic feelings of Physical Attraction an NPC might hold for a PC (or other NPC).

Now let's examine Persuasion.  This too uses Diplomacy but is differentiated from Influence.  The difference is, that Persuasion is goal-oriented.  The aim is to persuade the NPC to carry out a course of action.

As with Influencing Attitudes, the aim of these rules is to provide a fall-back for the referee who feels unsure how an NPC will respond to a given proposal.  There could be many situations where the NPC in question might agree with what a PC is suggesting because the DM can see that it is eminently sensible to do so and will clearly work in the NPC's favour or be of mutual benefit.  Or it may be that the player roleplays their persuasion so convincingly, that the GM feels it would be churlish to require a dice roll.  In such situations, which may cover the majority of PC vs NPC interactions, rules and mechanics are superfluous.

These rules are for less certain, or more challenging, Persuasion encounters.

My starting point for the system that eventually evolved, was the variant "This Old Rule" mechanic for D&D 3.5 Diplomacy from the giantitp forum.  It makes for worthwhile background reading but not essential to understand what follows. 

In that system the author eschewed use of Diplomacy as an attitude influencer at all and relied solely on the DM to rule what the NPC's attitude was based on their relationship to the PC; this plus the NPC's level plus some other modifiers set the DC for a Diplomacy check.  Conceptually this is reasonable, but in our campaign use of Diplomacy to influence attitudes in a general way to make enemies into friends is a pretty big part of the game.  There are also some class abilities, and also use of the Perform skill, that explicitly focus on attitude shifts rather than persuasion relating to specific proposals.  So my aim was to integrate both.

The thing to be aware of when doing so, is the "double dip" effect.  If a PC is phenomenal at shifting NPC attitudes in their favour, and this gives them an added bonus on specific persuasion checks that they are also going to be aceing, then Asmodeus may as well pack up and hand them his ruby sceptre and the keys to his palace by the time they're a mere 15th level (say).  This is why I couldn't use the "This Old Rule" mechanic without some re-engineering and recalibration.

First, let's introduce the idea of Proposition Levels.  

• Incredible: Extremely significant personal gains will occur, at negligible or no risk/cost in comparison; the opportunity of a lifetime!
• Fantastic: The reward is very worthwhile, and the risk/cost is low or negligible in comparison.
• Beneficial: The reward is worthwhile, and the risk/cost is moderate but more than tolerable for such a reward. 
• Favourable: The reward is acceptable, and the risk or cost is not insignificant, but tolerable for such a reward. 
• Even: The reward and risk are more or less even, or the deal involves neither reward nor risk. 
• Unfavourable: The subject is unconvinced that the direct rewards are sufficient to warrant the risks/costs involved.
• Adverse: The direct rewards are definitely not enough compared to the risk/cost involved; chances are it will end up badly for the subject. 
• Horrible: There is no conceivable way the proposed plan could end up with the subject ahead; signficant personal loss is guaranteed.
• Dreadful: Significant personal danger involved for the subject for no direct reward; with a high likelihood of dying.

Note that the PL is as much about the NPC's perception of the risks and rewards, as it is about the reality of the situation.

Associated with each of these defined levels, is a Proposition Level (PL) and a Proposition Factor (PF)

Now, the NPC will have a Diplomatic Attitude Grade (DAG) with respect to the player character making the proposition.  This might be a positive or negative number (or zero for Indifference).

We now have all the ingredients we need to determine the Diplomacy DC for the proposition.

DC = (PL x 10) + (ECL + Target's Wisdom Modifier + Circumstance Modifier) x PF - (5 x DAG)

Subject to one further constraint: the check automatically fails if the subject's DAG towards the proposer is less than the PL.  For example, unless the NPC feels "Fanatical" (DAG=5) about the PC, any Diplomacy attempt at a Dreadful proposition (+5) will automatically fail.  Roll anyway; success indicates that the NPC makes a counter-offer at the highest proposition level (PL) the PC could have succeeded at.  Failure by 1 - 5 means the proposition is simply rejected with no counter-offer; failure by 6 or more means rejection and loss of 1 stage of DAG.

Provided the subject's DAG is greater than or equal to the PL, however, the PC has a chance of success, as indicated by the DC.  Failure by 1 - 5 means a counter-offer at the next highest PL is made.  Failure by 6 - 10  means the proposition is rejected with no counter-offer; failure by 11 or more means rejection and loss of 1 stage of DAG.

Circumstance Modifier can clearly have a large impact on the outcome.  Note that negative modifiers reduce the DC; positive modifiers increase it, making the NPC harder to persuade.

Any special modifiers to Will saves that would usually apply to saves vs Enchantments, that are derived from feats, skills and class abilities (but not Resistance bonuses, and not the base save bonus derived from class levels) may be included as part of the Circumstance modifier.  Remember to include Flaws such as Weak Will.  

As per usual, immunity to Enchantments and mind-affecting abilities does not grant immunity to Diplomacy.  Using Diplomacy to persuade an NPC is not like a magical usurpation of their will.  The mechanic simulates their own decision making and the way in which it is swayed by the PC's arguments.

Note there is a lower limit to the value of (ECL + Target's Wisdom Modifier + Circumstance Modifier); this may not take a value lower than -9.  Practically speaking, there are very few situations where this is liable to occur anyway.  A 1st level NPC with a Wisdom of 1 has ECL+Wis Mod = -4, with Weak Will this becomes -7....a couple of traits might give another -2 to reach -9.  This would already be a very disadvantaged individual.

Formulas are too much maths?  It's Table Time, then

In a "typical" D&D 3.5 campaign, the first 2-3 subtables shown below will be those that are used.  If the campaign runs into Epic levels, additional subtables might come into play.  Using the formula shown above for the DC, with a little spreadsheet skill further tables can be generated if needed.

There is one component of the formula that isn't shown in these tables; this is the adjustment to the DC due to the NPC's Diplomatic Attitude towards the PC.

The higher the DAG, the lower the DC by 5 points per point of DAG.  In other words, as shown in the formula the shift is: 

        -5 x DAG

remembering that the product of two negatives is a positive, of course.

Example: an elven NPC, 10th level with a +3 Wisdom modifier and a +2 save bonus vs Enchantments, has a Diplomatic Attitude of +4 (Ardent) towards a particular PC.

Diplomacy cannot persuade this elf to do something Dreadful; for that, the DAG would need to be +5 (Fanatical).  Though a successful roll could lead to them making a counter-offer to follow a course of action that is Horrible from their viewpoint, such as adding extra conditions to the Dreadful request.

Let's see what the DC is to use Diplomacy to persuade them to do something Horrible.

ECL + Wis Mod + Circumstance = 10 + 3 + 2 = 15

Base DC for Dreadful is 100; but with a DAG of +4, this is reduced to 80.

This still seems unlikely.  Though a check result of 75-79 will prompt the NPC to propose a counter offer that is Adverse.  A result of 70-76 will result in a simple rejection but no hard feelings.  69 or less and the PC making the proposition loses Diplomatic Attitude in the eyes of the subject, dropping from +4 (Ardent) to +3 (Enthusiastic).  Making future persuasion attempts harder, of course, until trust is regained.

What is a more attainable result?  Well, to get such a character to a DAG of +4 is an accomplishment in itself, needing something like a typical Diplomacy check of 53 to achieve (assuming they were Friendly to begin with).  Then, with a check result of 55 on a Persuasion roll on the above tables, an Adverse proposition could be accepted (for example, some course of action that bore a risk of losing significant property, reputation or gainful employment, or the respect of friends or family).

There are other factors that might come to bear; for example, the elf in question may have friends who will advise against the suggested course of action.  We'll talk about such added complications in due course.