Ok, so this is something I've put a fair amount of thought into, and I felt like posting it, because I saw certain posts. People saying it would be a terrible idea, and people saying it wouldn't be, but giving some ideas that I find miss the point.

Now, when you think of Dishonored action-wise, there are 3 things it's built around. Movement, Stealth and Combat. Now, looking further into these in a "VS" point of view, in Combat you are either fighting a single person or a mob. In terms of competitive, fighting a mob of people would be tough unless you're killing NPCs for points, but that's already done in City Trials. So that leaves single-person duels. Stealth, in a "VS" fashion, is all about running and hiding, and Movement can really only be one thing unless you want some weird kind of competitive rock-climbing.

(Note, for the most part, it is assumed that people have Blink and Agility. You sort of need those things for any amount of mobility)

Combat:

So, for this game mode, the idea is an epic duel to the death. Many times when doing a Brawler Playthrough (no stealth. All sword-fights) I've thought about how much more interesting it would be to fight like this against people. One would think that this game mode would just be constant parrying ending with a pistol shot, but no.

First off, by default, I'd say Crossbow and Pistol would be taken out (although the idea is to have variants, so you could have one with the long-range weapons). Along with those, Bend Time and Grenades would be taken out for default. With all these things gone, combat becomes about the sword-play, and the main way to get an edge in Dishonored's sword-play: fancy footwork and trickery

At your disposal would be Spring Razors (not an instant kill), Choke Dust (shorter stun time), Possession, Windblast, Rat Swarm and most importantly, Blink. The idea in giving the player these to use, would be that they allow the player to escape/move, lay traps, and stun. While one could just parry and slash, it's a lot smarter to attempt to run in the middle of the fight and attack from a new angle. To do this, you could say, possess a rat and scurry away to try and get behind them, or possess/blink to hide and set up spring razors.

The idea behind this is to incorporate elements of Mobility and Stealth into the Combat-centric game mode, because as we all know, Dishonored is all about choosing how to approach a situation. However, as I said, there would be variants. Either it would have to be different versions in-which everything's preset, or you'd be able to choose a number of upgrades and powers/equipment and play with those like classes or loadouts in CoD or Halo 4 (although, I'd prefer there to be no unlocking and progression system).

For balancing purposes, damage on weapons would be decreased, and effects tuned back. Sleep Darts would make the screen go green and wobbly, and maybe effect responsiveness or movement speed, and stun mines would knock the person down for a second. Things like that.

Stealth:

For Stealth, let's take a page out of Splinter Cell's book, with a dash of Assassin's Creed. This one could work in 1v1 like Combat, or more people. Probably not too many, as I'd think 4v4 might be a little nuts. The more people, the less emphasis players would have on stealth, I'd think.

So basically, one team is hunting, one team is hiding: a good old game of cat and mouse. To encourage movement, the "mice" (I don't know what else to call the teams, so we're sticking with the metaphor) would have objectives they need to get to, and maybe hide at for a period of time. The "cats" wouldn't see them, obviously so that they can't just camp the objectives.

Now, the Mice can not attack except with mines and their powers would be Possession and Blink. They're goal is to either get to all the objectives (limited lives, possibly 1), or get as many objectives in the time limit (limited lives or infinite respawns), and to do so they need to avoid the Cats. As I said, to do this, they are given various traps and escapes. Spring Razor, Stun Mines and Arc Mines in order to lay traps and slow down your pursuers, and Blink and Possession to get them off your trail or escape them if they catch up to you. To explain more of what you can do, there's something with Cats necessary to bring up.

The job of the Cats is obviously to hunt down and kill the Mice. At their disposal is a Pistol, throwables (grenades, choke dust, etc), Blink, Dark Vision and maybe Pull (it seems a little too powerful, so if there's Pull, it would be in place of the Pistol). Now, there's one big tweak to one of these, which is what I needed to explain.

Dark Vision no longer shows people and items through walls (you still see sound). In this mode, it would show a breadcrumb trail. The way the Cats track down the Mice is by literally tracking them down and following their footsteps. The footsteps would be VERY easily seen, because of the fact that the Mice can break their trails by Blinking, jumping away, or Possessing a rat. The Cats would need to be able to spot the footsteps again (not like how visible a key is, say). This mechanic would 'cause the Cats to search the area for footprints, trying to outthink the diversions and traps laid by the Mice, ending with either a chase, cornering them in their hiding spot or just not finding them at all if the Mice are really good.. The Mice would attempt to make their trail broken and confusing, setting it up in a way for the "cats" to fall into their traps.

Again, this could have variants like the Combat game mode with changes to available equipment and powers, however, this could also have a more Combat-oriented variant. This is a tangential idea, but basically, picture the idea already given, but the objective of the Mice is the same as the cats: to kill. Due to the weakness of the Mice and their lack of swords, they'd be required to lay traps and attempt to lead the Cats into them. Just a side thought.

Mobility:

Dishonored mobility is about speed, spatial awareness and reflexes (no Daud Blink here). These are shown off in City Trials in Bonfires and Train Runner, and so: Races.

Small-man (possibly just 1v1) foot races would be Dishonored's Mobility-based game mode. There really isn't much to this one, except maybe throwing in some things to trip up your opponent(s), like Sleep Darts (as said before, just making them slower or less responsive) or Pull. You could also throw in NPCs to trip you up, like the Assassins in Expert Bonfires.

Races could be in Bonfires' randomized checkpoints system, or in Train Runner's finish-line system.

Level Design

This is just a guideline thing, basically saying the environments I was using to picture these game modes.

For Combat, I pictured the Back Alley Brawl map, as it has enough things to hide behind, enough verticality, and enough open spaces.

For Stealth, I pictured Clavering Boulevard and that general area (main area in High Overseer Campbell and Golden Cat). It's fairly big (although it could use more space on the Galvani side). I also pictured it with all the interiors being part of it, but that's just me.

For Mobility, I just pictured the Train Runner map.

And that's really it. Do you agree with these ideas? Do you have your own? Do you think Dishonored should never have multiplayer, even as a side thing or "City Trial"-style DLC? Feel free to discuss such things in this thread.