First off, I have no experience in modding or even how to create a proposal so this post will no doubt be full of flaws that you can pick up on, I just thought that it was a kind of neat idea that might be quite cool if it was made. Thats the hater-covering spiel out of the way, here's the concept:
The basic idea of this game revolves around clashes between the public and the police in riots.
(Taken from http://www.thescore.ca/sixpack/Riot-cops-with-guns-Reuters2.jpg)
The concept of the game is a realistic fps, team-based game using control points on the map that have to be defended by the occupier and attacked by their enemy. The capture points would be very similar to the capture points in DoD:S and the Insurgency mod (units have to be on that turf for a certain amount of time which decreases if more units are on it and is blocked if an enemy is on the same point)
The damage would be realistic, for instance a few hits from a riot baton would render a rioter unconcious (or 'dead' for the sake of respawning purposes)
The game would focus on intense melee combat between the Police force and the Riot force.
Riot Force Objectives
The objectives of the Riot Force team would be to push the Police back to their end of the map by securing control points along the way. As each control point is secured, the Police's spawn point moves back further until they reach the Police station which can be heavily defended to create an exciting ending to each map.
Police Force Objectives
The objectives of the Police Force team would be to stop the rioters gaining ground and, if they did capture any control points, the objectives could be changed by the captain to regain the lost points.
Weapons would mostly be melee, with the exception of a few gun-type weapons. Projectile weapons would be iron-sighted.
Riot Force Weapons
Anything that the Riot Force could find on the ground or in nearby shops could be picked up and thrown at Police. There would be select pieces of piping, bricks, wood etc that could be used as a melee weapon (much like Condemned: Criminal Origins). However, if a rioter took out a cop, they could steal their riot baton etc.
Each rioter would start off with the weakest melee weapon and one bottle to throw.
Police Force Weapons
The Police force would be able to customise their weapons in the start up screen. The most common weapon would be the stun baton and shield which would be used together with a 'right click for shield left click for attack' concept.
The projectile weapons would be a couple of rubber bullet firing snipers or shotguns and 1 tear-gas grenade launcher per team.
Each police character would start off with a baton.
When a player joined a game they would be confronted with a team selection screen, enabling them to choose Police, Rioters, Spectator and Auto-assign.
When the player selected their team they would then be asked which Unit (for Police or Gang for Rioters) they would like to join. Much like in Insurgency, each Unit would have different weapons to select depending on the level. For instance, one Police Unit may be exclusively melee.
Once the player had selected which unit they wished to be in they could customise their character.
The rioters customisation would be mostly aesthetic.
When playing as the Police, you would be able to select what armour you wished to wear (altering the speed at which your character could move) and what combination of weapons you wished to carry. For instance, you would not be able to carry a riot shotgun and shield with baton together, if it came to melee fighting you would have to rely on fellow officers to defend you.
Using the unit command concept similar to Insurgency, one player per unit could issue orders to the rest of their unit.
Maps would consist of heavily built up urban environments such as city streets, shopping centers and housing estates.
There would be more than one linear way to reach each control point, such as back alleys, sewers or straight down the main route!
The Rioters would start at one end and the police would start at the nearest control point to them, immediately placing players into combat. This would also allow the Police to be pushed back by the Rioters. (Something would need to be done to account for spawning camping etc but this is just a preliminary idea!)
The final Police location would typically be the Police station which would be the final stand of the Police. It could also be any well defendable area of the map. This would allow for exciting final stands and skirmishes.
How are Rioters better than Police?
Could be more of them
Move faster due to less armour
How are the Police better than the Rioters?
Initially better weapons
Only the Police can issue orders to their units, the Rioters are too much of a rabble to allow this.
Further Ideas to Consider
Rioter versus rioter:
The Police have to stop two rioting groups from attacking eachother in a three way large scale clash. Will the police join forces with one riot group or will they be raped by both riot gangs.
Recreating Historical Riots:
Using accurate maps and perhaps changing the character skins, you could create re-enactments of existing riots. What about the Rage Against the Machine riot after they played outside the Democratic Convention 2000 Or riots in Ireland with IRA etc? Have to be careful here about pissing people off though!
It might be cool in integrate guns for the rioters such as haphazardly crudely made rifles, illegal handguns, sawn-off shotguns etc.
Anyway thats my idea, just thought it would be kind of cool to see made and if I had ANY 'mad 1337 skillz' at doing so I would probably give it a try.