Fragile alliances

To go along with the previous comments: It would kind of be interesting if you had a deck of skill cards that each player randomly grabbed. Some could be mundane skills like speedy +1 movement. But other skills could be essential like safe cracker +5 vs safes. But each player would have several skills.

Players could share which skills they had if they wanted too, but wouldn't be required too. That way, you would never truly know how valuable/dangerous another character was. There might be duplicate skills or the same skill at varying proficiencies. So you might have an expert safe cracker and a good safe cracker on the same team.

This might lead to another interesting gameplay, namely players lieing about what they can do to stay alive.

Concerning what to do with the dead players though, because no one wants to watch others play a game while they sit. You could have the players who die control certain cops. That way they can focus on getting revenge, which puts betrayal as a negative thing; but essential to win.

Just a thought.

Those are all really good ideas. I had one other idea, that perhaps it is worth bouncing off of you, and seeing what you think:

This would take some playtesting to get used to, but you could make the enemy tough enough such that if you have an all-out civil war at the start, you'll likely loose. Say, you have 4 robbers, each robber can on average take out 10 cops before dying, and ~30 cops to fight. If you dropped to 3 at the beginning, there is a semi-reasonable chance of party survival. If you drop to 2, it's really unusual. If it's just 1, you're screwed.

Of course, that would only need to be the case at the beginning. Perhaps, after you have killed 10 of those cops, you start wondering whether player 2 is really pulling his weight, and perhaps you can take him out without seriously hurting your chance of victory.

Again, this would need to be tested a good bit to hone the game to this level, but if you could do it un-forced like this, that could be really cool.

The way it would work is this: Let's say everyone has 3 skill cards. Each card would be drawn from a seperate pile (Tier 1, 2, and 3). Tier 1 abilities would be the weakest (+1 against other players) and Tier 3 abilities would be the strongest (+6 movement). Each player would recieve one face down.

At any point during the game, the player may reveal their card to use their ability. Until the card is revealed, the player plays as though he has no special skill. So if you don't reveal the movement card, you move the standard rate. But when it comes time to really get out of the bank, you can reveal it and use the skill modifier from then on. You can choose not to have the ability revealed so that you can lie about what it is.

Or, if you choose to use just standard abilities, give each player two abilities, one early game (good at taking hostages, for instance) and one late game (good at killing cops).

I also like Simons' idea. The cops would be so numerous that it would take everyone to fight them off, and it would be a gamble to kill anyone.

One thing you need to be very very careful with a theme like this is games that kill cops generally don't get published, get blacklisted, and don't get purchased; and frankly speaking rightfully so. However, slightly re-theming would allow you to keep the same game mechanics. Even if it is the wild west. It is okay to shoot a western deputy that no longer exists; but busting a cap in a police officer gets some on edge.

Concerning the hidden skills, I have a game where we hide the skills from one another. Each player must know the rules, and when they roll they keep their rolls hidden. When they roll against each other or against the game they don't say what they rolled plus their modifier, rather they just say their net roll. So for example I rolled a 4 but I get a +2, I simply say I rolled a 6. If you play with someone who is going to lie and cheat on a game, chances are they are 12. :) A game like this wouldn't work with people cheating.

But with that said, this again would bring up some really interesting dynamics, such as if I had move +6, I might let people "accidentally" see my roll, then only move +3. That way, if I had to survive in the end I could bust out a +6 move and everyone would be thinking and planning that I could only move +3.