I've been creating my own campaign loosely basses on the Eberron campaign setting (as in very loosely, I've only been using the names of countries & cities to create my own map). I was planning on having the races go into a war for the continent, but I don't know how to set up a battle in this format. I don't want my group to be just some insignificant soldiers, but I also don't want them to feel that they are completely in control (as they are only level 2). It is a small party, (3 characters including mine) and none of them are a rouge. One is an orc fighter, another is a human cleric, and my character is a human ranger. How should I set up encounters so that they feel like they're fighting in a war but they don't feel like their doing nothing?
There are several possible solutions and it most likely depends on what you have in mind. War isn't all about "stick them with the pointy end" after all. Try to figure out what your team is good at or would like to do. There are many things they could do to aid the war, without having to even think of it as a war setting.
Perhaps they could negotiate an alliance with the tribe of mountain goblins near the war for extra aid to swing the battle?
Perhaps there is an ancient mausoleum located roughly underneath the central valley where it is said an army waits entombed to serve?
Infiltrate the enemy camp and assassinate some of their leaders and poison their supplies?
If, however, you prefer to have them fill out some sort of combat role, you could have them fighting in skirmish fights to the side of the battle where they can prevent the enemy from gaining a foothold. Have them defend a bridge or try to breach a poorly defended fortress.
Hell, if you want to spice up your gaming format you could even try a solution outside of 3.5. There are a lot of tabletop wargames, if your players would like a try at something simplified like that you could play out the battle and have their characters as heroes in the 'minigame'.
Give them a strategically significant mission with no or limited backup, possibly behind enemy lines.
In that way, they have control over their particular battles and might even have limited communications with their superiors. Their actions are significant in that it has strategic relevance, but not decisive to the whole war and they certainly aren't in control of the whole war even if their part becomes decisive.
For examples, consider a mission to steal an artifact, destroy a significant building (perhaps a storehouse for grain), or if you are willing to go darker a strategic strike to kill a particularly important person on the other side.
I would draw some inspiration from the way AEG does mass combat in L5R and 7th Sea. Even if the characters are authoritative in some way, they could just be handling one leg of the battle, and thus their victory is small scale and preserves the lives of their side even if the over arcing battle itself is a loss. Their actual system streamlines things to a degree that is less conducive to the d20 system however the bit I think you'll find most useful goes like this:
Each mass combat round, each PC has the chance for what's called a "Heroic Opportunity". These are things like:
This isn't by any means the exhaustive list of things that could happen but it's not all stand and fight in a meat grinder. PC's could team up or take challenges singly although these games were more individually enabling than the d20 system so be careful when implementing.
Our group has the following setup whenever there would be a large scale war:
Our characters meet and discuss strategy and thats what will most likely be going on in the background as long as it doesnt require our direct interference (an assassination or sabotage would be direct and we would play those encounters out first). When battle time comes, while the war is raging around us, the DM sets up quick encounters for each of us, a heroic time to shine. The DM's job in this scenario is to provide the proper amount of tension and drama as the battle goes on, adjusting difficulty on the fly.
In general, it boils down to how every movie with a war ends up. Yes there is chaos all around but the camera focuses on a couple of the main "players" with occasional cuts to the larger picture. The players are the main "heroes" of the game. As a DM, try and set that feeling up for them so they truly feel like they are part of something epic.