Sanity is the lifeblood of Cthulhu. It comes into play more than any physical resilience investigators have contested. This makes sense -- Lovecraft's work hinged around sudden insight into things that should not be. For a character that you intend to stick around, this means that SAN is by far the most important thing on your character's sheet. Sanity starts at POWERx5, and POWER is on a 3d6 roll. That means your average investigator will generally have less than 12 POW, or 60 SAN. Only about 37% will have higher than 55 sanity.
The Mechanic of Sanity
For those of you who aren't initiated into Cthulhu, Sanity is contested similar to a skill check. When you roll at or below your SANITY value, you pass, much like a saving throw in another game. When you fail, you take damage to your sanity value as if it were a hit-point pool. When that pool reaches 0, your character is permanently out of play. That's not the only bump on the road, however: if you ever lose more than 5 points of sanity at a time, you have to make an IDEA save (similar to an INT check). If you pass, you become temporarily mentally ill (but remaining in play). If you fail, you give in to gibbering nonsense for the rest of the scene. If you ever lose more than 1/5 of your SAN score in the span of one in-game hour, you gain a permanent illness that can only go away with long-term treatment. Here's a quick table of sanity damage compared with death metal songs representing the level of trauma that one would need to incur.
| Appropriate Death Metal Song Title | If Success | If Failure |
| Decapitation of Cattle | 0 | 1D2 |
| Milk and Innards | 0 | 1D3 |
| Ominous Bloodvomit | 0 | 1D4 |
| Hobo Stew | 0 | 1D4+1 |
| Colostomy Jigsaw Puzzle | 0 | 1D6 |
| Embalmed Yet I Breathe | 1 | 1D6+1 |
| Bathing in a Grease Disposal Unit | 0 | 1D10 |
| Evisceration Plague | 1 | 1D10 |
| A Living, Breathing Piece of Defecating Meat | 2 | 2D10+1 |
| Dead but Dreaming | 1D10 | 1D100 |
The Slippery Slope
Because failure at a Sanity check lowers your Sanity score, players engage in a slippery slope to avoid sanity, doing everything they can to avoid the horrors that a scenario has to offer. Cthulhu quickly devolves into a game about intelligent investigators doing everything they can to never read or see anything, remaining as ignorant as possible while letting their compatriots be subjected to unspeakable horror. The only players brave enough to try are the ones who happened to roll high on their POW roll at character creation, and thus are relatively immune to the Mythos. Where other players scramble away, they yawn, nod, and accept this. While each individual roll might provide resilience, the higher the sanity score, the more likely a character will remain impervious to the horrors a scenario might provide. Consider this graph comparing sanity scores with the percentage chance a character might succeed multiple attempts. A character with a 90% SAN is largely unfazed by 6 consecutive checks when compared with someone at 80% SAN.
The Benefit Does Not Stop There
Given that players have to save or become unplayable any time they lose 5 points of SAN in a single roll, the graph below shows the likelihood that players with a specific SAN score will go temporarily insane. As you can see, a character with 85% is largely impervious to any trauma short of meeting Cthulhu himself.
In my experience (straight off memory), the average player has to take one 0/D2 or D3 sanity check, two 0/D4 or 0/D4+1, and 1 0/1D6, with a big finisher of a 2/1D10+1 when the unspeakable horror is revealed. The D6 and the D10 are usually within 1 hour of each other. I began to run statistics on the likelihood of going permanently insane (losing more SAN in an hour than 1/5 your starting SAN score), but the numbers became so impossible that I failed a few sanity checks myself. If you're particularly in the mood to try your hand at a puzzler, I'd love to see the percentage chance that people at any given score can survive that spike of SAN loss. Here's something to get you started: with 10 SAN, you have a 0% chance, and above 85, you have a 100% chance.
Usually if you are hitting the point where you are suffering the 2/1d10+1 SAN loss, it is because you've screwed something up and are in over time to fix it before it completely falls apart. So, I think it is best to ignore the big finisher. The other problem is that players tend to investigate in a fiercer, more dedicated manner than a real person would be able to do so, so you should have slightly more buffer space. I think the other problem is that the game is a bit weird about sanity loss. On the one hand, anything horrifying seems like it should trigger sanity loss, but mutilated bodies don't seem to be on the same horrifying level as say, monsters.
ReplyDeleteI think one way to help smooth out the sanity loss is to make mundane things not cause sanity loss, which turns sanity into less a measure of someone's total sanity, and more a measure of their direct relation to the mythos. Which makes gameplay a bit smoother (now dead bodies and the like don't risk removing players from play), give you more sanity to deal with on important plot events, but at the cost of making sanity less sanity and literally just a resistance check. So, pros and cons.
For each of these articles, I'm going to be posting a GM counterpoint, both from a running perspective and a scenario design perspective. I agree that dead bodies shouldn't be removing players from play.
ReplyDelete6th added the caveat that after you take a SAN loss from seeing a Deep One, you should be immune to seeing Deep Ones 'til the end of the scenario. That was a huge step forward. I'm also toying with the concept of fridge horror, where players are hit with the Sanity check not when something's read or seen, but at the point where it becomes fully realized in the plot. It specifically bypasses the "Well, I didn't read it" attempt at manipulating, and it ties it to an event.
I'm a little stumped at how to smooth out the curve so that certain players aren't nigh-immune to a core game mechanic, short of point-buy (which there is no rule for).