Unlike the multiplayer or the singleplayer, there has never been an official co-op mode in the BioShock franchise, which means no base model to improve or develop on. This also means my co-op weapons don't have any predecessors to base themselves upon, so most of my ideas here are purely guesswork. However, co-op implies a few constants remain which will determine how the following weapon system will work. The two main constants here, in my opinion, are choice and balance.
Co-op, the way I see it, is all about replayability, since you're going to be going through the same levels over and over again with friends. Thus, if there is to be a weapon and upgrade system in the game, it has to be flexible enough to accomodate for variety. My singleplayer system, along with the one present in both BioShock games, don't allow for much flexibility, mainly because they rely on deep specialization, i.e. you have to dedicate a lot of time and resources to unlock certain aspects of a single weapon. This is why I think there needs to be a new system, specially adapted for co-op: variable upgrades.
What I mean by variable upgrades is the following: instead of buying one fixed upgrade for a weapon that'll stay with you for the rest of the level (you can change upgrades no matter what between levels, I'll explain that in further detail in another article), you simply sink an "upgrade point", or something like that, into the weapon, allowing you to outfit it with one extra upgrade which you can change at will at a Power to the People station. Every new PttP would give you one extra upgrade to sink into a weapon of your choice, as per normal, and in my system you'd have a total of six different, readily available and equally powerful upgrades to choose from for every weapon in your arsenal. Now, this is where the balance aspect kicks in: for every weapon, you'd only be able to unlock a maximum of three upgrades at a time from its upgrade pool. This is mainly to avoid min-maxing your weapon set (so in the end all of your weapons will have three upgrades to them), but also to avoid putting you at an advantage/disadvantage relative to your partner, especially considering that I'm planning to include partner-versus-partner combat in certain in-game situations. On a side note, the fact that you can change upgrades and combinations at will would give the player a choice of twenty different combinations per weapon, once you get to choose three upgrades for it.
To further elaborate on the more technical aspects (in other words, skip this section if easily bored), the balance constant also implies that every ammo type has to be as powerful and useful as the rest for any given weapon. Therefore, don't be surprised if my ammo types present certain disadvantages relative to the basic versions. Basically, it's like coming up with weapon ideas for the multiplayer (which I did, see here), in that every addition to the weapon is supposed to be both interesting in its own right while keeping you on the same power level as your fellow player(s). Now, for the really technical bit, the Power to the People interface would have to change to avoid flooding the player with an endless and confusing list of upgrades: as with my singleplayer version, the list would only display the weapons in your arsenal, and clicking on one of them would open up their personal upgrade interface. Since I plan to include six available upgrades for every weapon, every upgrade icon could be arranged in a wheel/hexagon around the main weapon icon, and hovering over each one would bring up its description. The weapon icon could also have a counter to indicate how many more upgrades you can add to your weapon, as well as how many upgrade points you've sunk into said weapon. In addition, the upgrades you'd have chosen to outfit your weapon with would have their icon encircled in a golden ring, or something similar, to indicate which ones you equipped. To change upgrades, you'd have to deselect an upgrade first before choosing the new one (unless, of course, you have upgrade points to spare). Also, although with six upgrades it's a bit of a stretch, it would be best for each one of them to change the weapon's appearance as with the other game modes.
NEW!: In addition to variable upgrades, I had another idea which could cater to the co-op mode's replayability value: variable ammunition. Basically, instead of having just one kind of rare and super-rare (or, in this case, inventable) ammo, you could have a choice of three each, which you could switch out simply by picking up the alternate ammo you want to keep. That way, not only could you adapt more readily to any potential occurrence, you could also play a level with a completely different ammo setup and have an entirely new experience all over again.
List of Weapons
- Music Box Gun
- Tri-Barrel Shotgun
- Harpoon Launcher
- Hack Tool
- NEW!: Tool Kit