(help please) Mechanic for simulating PC insanity due to use of psionic powers?

[cincinnati reds]

Hello, all;

For a campaign I will be running following the new year, I'm looking for advice on how to create a house rule which would model a PC's chance of slowly going insane due to use of psionic abilities. Lower-level powers would pose little rick to PCs, but the regular use of higher-level psionics would pose a threat of the PC slowly losing his/her mind. Does anyone have any ideas, or even where I would begin?

Thanks,

CR

 

[DanMcS]

How insane do you want them to go? How quickly?

You could use a saving-throw type mechanic, where every time they use a power they must make a will save themselves vs an equivalent DC or take 1 sanity damage (or 1d6, or whatever). Then you just have to decide how long the damage track is (20, 100, or (1+charisma modifier)*(class level) would all work, depending on the tone you want), and if it's possible to regain lost sanity. For instance, if they manifest a 1st-level power, they make a will save vs 11+ their own DC stat modifier (int bonus for psions, I think). If it's a 9th-level power, then the DC is 19+ their modifier. This has the advantage of scaling with powers like you want, and also means that a high-level psion won't have to worry too much about his low-level powers, but his best powers are as dangerous to him now as they were at low levels.

Unless psionics are the only kind of power (no arcane or divine) in your campaign, then making this too dangerous will just mean no-one will ever play a psion. If that's what you want, then it's simpler to just not allow psionics.

 

[cincinnati reds]

Psionics are the only type of power in this campaign, yeah.

The idea I'm trying to model with this rule is "psions have great power, but eventually they all go mad." I don't want low-level psions to worry about going mad, but as they gain greater access and realization to what psionics actually are and where they come from (heh-heh), they start becoming unhinged. Sorta like a psion can handle the low-level stuff, even if he is a low-level PC, without breaking much of a sweat, but once he gains greater power, that power starts breaking his mind.

A Will save seems like the right place to begin with this. Perhaps something like powers of 4th level or higher require the Will save at DC10+power level*1.5? I'm not very good at math, unfortunately - would that curve so that higher-level powers are exponentially more dangerous to use?

As for a damage track, perhaps giving the psion a number of Sanity Points equal to his CHR (I use CHR for Will modifiers and WIS for Init modifiers) and when the SP hits zero he permanently loses a point of CHR but then he regains SP equal to his new CHR?

Does that model well? I know it's inelegant as hell.

 

[the Jester]

Warhammer FRP, Unearthed Arcana, Call of Cthulhu and the 2e Players Option: Spells and Magic all have good ideas on these things.