Players vs. players

[malloc]

I have an idea for a play-by-post game on rpol.net. Two teams of players: one is the Heroes and one is the Villians. Because it is play by post, I can actually keep each group's conversations private from the other group, so they can scheme against each other.

Has anybody run a game like this before? I am wondering what problems I might run into with players playing against each other rather than NPCs. Are there certain powers which might prove problematic?

Also, anyone have ideas for encounters? So far here is what I was thinking.
The players are a group of heroes in a crime-ridden district of the city. They help the police keep order in the area because a powerful mafia group is located there and increasing lawlessness. The villians are the super powered muscled for the mafia group.

My ideas for encounters so far are:
Protect:
Based on the Heroes activities the mayor of the city is coming to the district to give a speech and help instill hope in the beleaguered populace. The mafia bosses want to make a statement by kidnapping him and ransoming him back to the city. The Heroes need to make sure the mayor stays safe.

And on the flip side, due to the Villian's success in keeping law and order out of the district, a summit of national mob bosses is going to happen in the District. The police give the Heroes a tip to the location and the Villians need to keep their bosses from capture and imprisonment.

Infiltrate:
The Villians are working collaboratively with a group of satanists to open up a hell mouth in the district, allowing demons and other evil creatures to travel there with ease. The process involves a ritual surrounding a certain Macguffin hidden in the lair. The Villians need to keep the Macguffin safe for 24 hours for the ritual to succeed.

And on the flip side, a national super agency has agreed to install a Justice Lab in the district. This is a high tech training program for young Supers to ensure they end up on the side of good. Since the facilities are huge targets for villians, a super shield needs to be erected around the facility using some piece of technology that the Heroes need to keep safe for one day.

I would be really interested to hear if anybody has any other ideas for a PvP MnM campaign.

[poodle]

that's a great idea...I wanna be a villain. The major problematic powers as always are precog, mind-control, possession and mental transform (I think) although total conceal can be a bitch to deal with. Mimic might also be problematic to sort out the mechanics for. Emotion control and confusionare others that are trcky to make players be a part of.

Again I think it is an idea that would only work on play-by-post.

[Kariggi]

Invisible with subtle/insidious attacks

[poodle]

man there are so many ideas that would be funny. Just think of any criminal movie.
The criminals have to find a way to neutralise a supers team. The super team has to catch the ctiminals in the act.
The criminals have to steal an object of x value, the supers have to work out which one.
The criminals are trying to get elected, using bribery and corruption. The supers want their own candidate to win.
The criminals have top capture a super to convert to the dark side. The supers have to escape and thwart their evil plans.
The criminals are holding a children's hospital to ransom for money. The supers want to rescue the children.
World war 3 is brewing. The criminals are trying to take over the government but the supers are trying to stop them.
easy one. An alien comes to find the strongest group to bargain with and arranges a gladitorial combat of good vs evil.
Jailbreak...the criminals are trying to start a crime spree by breaking all the superfelons out of the toughest max-security prison that they know of.