I don't normally do the editorial style posts but this is something that has been churning over in my brain for a few weeks if not months now and I want to get it down onto paper/interwebs. I apologise now if this comes across hugely rantish. I've recently seen a case of tournament organisers going away from varied missions in an effort to maximise balanced missions. This includes things like defining where objectives are placed on the tables (12" in from the long table edge, 18" in from the short table edge, etc), to making changes to how kill points are dealt with in an effort to achieve what they feel is balanced. Well I cry bullshit.
I can go to places like 3++ and find lots of well built lists that are designed to smash face based on stock standard missions (I'm not having a dig at Kirby and the guys on 3++ just pointing out that they are very focused on list building and tactics. They do it well and their lists work well in established missions, but due to their nature of being optimised to work with standard missions, they may not work as well when you have non standard missions). When someone with one of these kinds of lists comes up against an odd ball mission (my Milk the Cows mission from COWCON 2010 is a good example), they cry foul that the mission isn't balanced and shouldn't be used. Before we go further though we need to establish what is and isn't a balanced mission.
These are the kinds of missions where the objectives have a great chance to advantage or disadvantage a given side. Examples of this are things like wildly scattering objectives or objectives that hurt things around them when they arrive. I played one mission where the single objective did both, leading to my mate's Deathwing army getting killed by the objective arriving and a poor scatter whilst I had the unfortunate situation of having to charge across the table to my enemy's deployment zone to try and secure it whilst he got to sit there and shoot me up.
In short a unbalanced mission is generally one where the nature of the mission immediately has a good chance to greatly skew the results based on chance, not because it favours one type of army over another.
These are the opposite of non balanced obviously. They have little to no random luck involved and are often based around existing idea (like those provided in the rulebook).
Now if we have a close look at the missions from the rulebook, you see some based on capturing objectives or multiple objectives, to those based on killing as many enemy units whilst minimising your own losses. These different types of missions often make it difficult to build an army that can secure multiple objectives whilst having a low amount of kill points, the result of which is a compromise. A force built around having a low amount of kill points often finds it difficult to hold/and or contest multiple objectives due to its limited amount of units. A force with lots of units will have an easier time of holding and contesting objectives but finds itself giving up kill points much easier. A force that combine the two might find itself disadvantaged when facing an enemy that excels at one type of given mission when it gets the right match up.
Recently I've seen a case of people trying to adapt the various missions from the rulebook to make them easier for one type of army or another to complete. Examples of this are restricting the amount of kill points available or by fixing in place or reducing the amount of objectives. This doesn't fix anything however. The result is that one type of army style or another dominates the scene as when you give strength to one type of army, you're reducing the impact of the strength of another. If you want to reduce kill points, that's fine, but expect most lists to be MSU style affairs because you just made them stronger. Don't like objectives, give the minimum kill point guys a boost.
So my point here really is stop trying to make missions "fairer", make them more interesting and get people to build the lists that suit those missions. I've had people complain that they felt my Milk the Cows mission which requires people to take an objective and then hold it for as long as they can, hurt their army. Sure it did, because their list was built around the last turn objective contest. Build a different list, if you're list doesn't do that kind of thing well, change it so that it can. Add that sub optimal unit that just so happens to fill the gap. Adapt. Be a better general and learn how to handle the curve balls rather than complaining that the mission was unfair. You built you're army around the missions in the rulebook, well here's a new one to add to the mix. Try it out, adapt your army to suit, and then move on. The mission isn't unbalanced because it is unfair, it just seems to be unbalanced because you hadn't planned for it.
In the end, the powerhouse lists are built to excel at set mission types. When the missions change, and you want a powerhouse list, you will need to change it also. That's the nature of the game. This is why the lists that people took in fourth edition 40k are different to those in fifth. The missions changed and what was good became less so, and what was less so often becomes good.
Lastly, I'd like to make a note on fixed objective placement. Ditch it please, it's insulting. If someone plays an all biker army and I put the objectives in difficult terrain, that's his problem for taking that style of list, and he or she should plan for it accordingly. He or she can still place his objective out in the open. All fixed placement does is change it into a game of chance as to whether that particular spot will have terrain in it or not.