The Call of Cthulu

So I have come to the conclusion that the only actual way to play Call of Cthulu is to not tell your players that you are playing Call of Cthulu. Hilarity Ensues

That would be fairly interesting IMO.

yeah, just not sure what system I would run it in. D20 modern would be the least suspected. I'm sure some one made a CoC system for it. Just don't know how well it would really loan it's self to the world.

In game system terms CoC has a lot in common with other D100 systems. It would be fairly easy to run say Astounding Adventures pulp (BRP) for a while and gradually introduce Mythos elements. Or you could start with BRP Rome and switch to Cthulhu Invictus without letting on. Or if you prefer Savage Worlds I believe this can be used with the WW2 Achtung Cthulhu books (I can't recommend that personally as I haven't tried it, but some of my group have the AC books so I might end up playing it sometime soon)

Why couldn't a person just improv it. It's not like you truly need stats for the horrors of the elder gods. You just need a combat mechanics for any cultist you encounter and maybe some of the lesser creatures, skill mechanics for the investigating stuff, and a sanity mechanic. The rest a person just wing it since it is mostly theme dressing, right?

Yes Metroknight a GM can do it all with any system if experienced enough.  I don't know whether William P and Kabius are long-term GMs or not. Or if they are comfortable changing rule systems to include a new genre. You are right that the skill mechanism and sanity rules are the important bit not monster stats! Some systems (e.g. BRP) already have skill mechanics and optional  sanity rules so it would be easier to introduce CoC material into those without major upheaval. Just introduce  some new skills  or specialisms (e.g. Research, Knowledge(Occult)  ) to your existing campaign  building up to the first  stomach  churning, insanity inducing  reveal. 

I am hella surprised people don't want to play Call of Cthulu, that is such an interesting game.

I remember reading about someone that ran a Cthulhu styled game in D&D and that is why I was wondering about just improving it.

I personaly don't think i could run CoC right. I've game mastered for somewhere between 12-15 years, and I'm pretty good. But I know that CoC is something that I don't think i could do "right." But yeah, i'd have to actually check up on the CoC rules and find something that would work in another system for sanity and what not. The reason I say D20 modern is that it would a) be the easiest to get people into. B) they would make semi normal characters. c) allow me to tell them that they are playing as investegators or what not in pretty much any timeframe in the last 150 years, without rising suspicions.

Gurps should be usable also for that type of setting.

I have 0 experience with gurps. I might mess around with it some time. Busy with SR5 for now.

I have to agree that D20 modern is probably your best alternative to CoC. The mechanics are fairly straight forward, people tend to be more familiar with the game mechanics and style, it allows you to make crazy nightmare creatures fairly easy etc. 

Can always try using the All Flesh Must Be Eaten Unisystem....there is a fear table that makes it so you can get players to lose their minds or just have a bit of chills and shakes,

I just found out that M&M3 has a supernatural sourcebook that refers to cthulhu in their examples.

GURPS may be the best way of going with. an option I'd suggest is using the cyberpunk game. Start by having the players play GURPS cyberpunk , then slowly introduce things from another book Cthulhupunk . Now you have the players on edge, as they no longer have sure footing of what genre that they are playing in. it also means you can catch them by surprise. you may go is the opposite way, use the player's own knowledge of the lore against them. a good game to try this out with is the laundry . as the game operates under the assumption that the players are familiar with the Cthulhu mythos and will occasionally throw them curveballs such as deep ones not actually being a threat.

I like the GURPS cyber punk idea. It would definatly allow people to feel comfortable thinking they know what game they are playing.