I was discussing this idea with my brother when I saw him the other day. I'm almost positive this has been talked about in the past on here, but as far as I know it's never been considered for modern wars.
The idea we were talking about is, as the title says, hostages. Where the enemy team can capture one or more of your troops and remove them from combat until you free them. I'm honestly surprised this hasn't been brought up before when planning gametypes for wars. I suppose the big downside to it is that anyone who's being held hostage doesn't get to fight, and could potentially stay a prisoner for the whole game. But that can happen in 1HK or other elimination games as well. I think it would be fun to incorporate the hostage mechanic into future wars, and might be a breath of fresh air. We haven't really had any new gametypes lately.
So there are obviously several different gametypes involving hostages that you can play. The first is what I'm calling Rescue the Hostage, or RTH. Feel free to come up with a better name if you want. This game is single sided, and the first half plays very much like 1-flag CTF, except the defenders (I suppose we can call them "captors" in this case) are guarding a player from your team instead of a flag. Throughout this description I refer to the rescuers as "your team", and the captors as the "enemy team".
The hostage can only rejoin your team and fight if he/she is touched (or untied, if you want to be realistic about it, hahaha) by one of your players. From then on, the objective is to escort the hostage back to your base, in a similar fashion to VIP Escort. The hostage can either be given a gun, or go weaponless.
Now, when an enemy is hit, he/she must respawn at the other end of the battlefield, near your starting point (which could also be your spawn point, to make things interesting; otherwise your team can just respawn away from action). This way, if the hostage is rescued, the enemy is in position to try and stop your team from making it back safely.
Your team wins when the hostage is escorted back to your base. The enemy team can win in two different ways. One, if the time limit runs out before your team can rescue the hostage from the enemy base, at which point the enemy may execute the hostage by dumping water on them if they so choose. :p Two, if a player on the enemy team makes a hit on the hostage while he/she is being escorted to your base. Note that after the hostage is rescued from the enemy base, the time limit stops counting. This game is basically a combination of 1CTF and VIP Escort. It is a relatively complex game, but I think it should be manageable. Obviously tweaks can be made, and any suggestions are welcome.
Another game involving hostages doesn't really have a good name. Maybe Capture Them All (CTA) or Roundup or something. This game is symmetrical/double-sided, and starts out just like 1HK or 1HS. The difference is, you can capture enemy players, and the game is won by whoever captures all opposing players first. A time limit could be included, and if it runs out before a whole team is captured, the winner is simply the team that made the most captures. This is because the game does have the potential to just keep going on and on, which some people might not like.
There are several different ways you could possibly capture someone. For one, you could just shoot them. This would basically make the game like 1HK, but giving teams a chance to bring back their eliminated comrades. To make things more interesting, capturing a player could involve an additional step after shooting them. For example, you'd have to touch them while they're trying to respawn, or maybe shoot them with a squirt pistol or something. I haven't really nailed down a capture method that I'm completely satisfied with yet. Any suggestions?
Respawning (if included at all) is simply done on the spot, as that would make for better chances of making a capture. Spawn times could either be long or short depending on what you want. Longer times give more opportunities to capture, but shorter times might make for more fast-paced action.
Once a player is captured, they must go to the enemy base, where they must wait until a member of their team comes in and touches them or whatever. Unlike the previous game, tying them to a tree or a chair wouldn't be very practical here, haha. I think this would make for some very interesting offense/defense shifts. Though my predictions may not be accurate, I can see this game being absolutely chaotic. It reminds me a little bit of Freeze-Tag, which I played in Nerf a couple times. I suppose we could try playing that as well. It would actually probably work better in water wars due to the shorter engagement distances. But that's another topic.
Hopefully I covered everything. Of course there are many other possible games that can utilize the hostage mechanic; these two are just the ones that I came up with. Feel free to think up your own. I realize that there's a lot of text here, but I tried to split up the paragraphs to make it easier to read. I am definitely interested in trying these games out sometime, just for a change of pace if nothing else. I think Soakemore would be a good war to implement it. On Sycamore Island we could put prisoners in the treehouse, haha. If we do it in the Labyrinth, the double sided game would be better.