|It's a shitty job, so use a spell|
These are Caustic Mists, Storm Ravager templates, Scather Templates, Covering Fire templates, and the many other options the game offers to put down patches of damage dealing ground. We can use these buffers to deny an opponent access to vital areas on the table with a part of his army, depending on the nature of the buffer in question (Corrosion, Fire, Lightning, how powerful the damage etc. etc.).Damage
Blocking Line of Sight makes for a wonderful buffer effect. The ability to declare a charge is vital for the threat and hitting power of many models in the game, and removing that option severely limits the options a model has available. A Warjack/Warbeast could trample through the cloud but it will cost it a Focus/Fury and all it's initial attacks, thus cushioning the impact it has on your army.Line of Sight
This type of buffer is heavily dependent on your opponents list. In some games they will be completely irrelevant and in other games they can win you the entire game with one application. A well placed patch of Rough Terrain can take entire units or heavies out of the game for a turn or two while they struggle to get into position.Rough Terrain
These buffers create artificial obstacles or obstructions. These can be used to stop non-reach models from physically reaching your army, granting cover, or blocking lines of effect. These are some of the hardest buffers to use correctly but also some of the powerful buffers in the game.Obstacles
Many buffers have more than one buffer ability, making them much more powerful. The most common combination is Line of Sight combined with Damage, which we find with Caustic Mist (Lich Lord Asphyxious), Mage Storm (Black 13th), and many more. Pillars of Salt (Mohsar) combines Line of Sight with Obstacles. Rapid Growth (pBaldur) combines Rough Terrain and Line of Sight, and a select few buffers combine three aspects like Eruption (Karchev) which blocks Line of Sight, deals Damage, and is considered Rough Terrain.
It's impossible to determine the correct way to apply buffers to a battlefield, as the best way is always determined by the battlefield and positioning of models on it, but there are some basic guidelines that should be considered when you have access to buffers.
- Use what is already there.
- Know what you're up against.
Dealing with buffers
Being on the receiving end of a buffer zone is brutal, and most of them can't be moved or ignored. The only thing you can do is to acknowledge the possibility that buffers will impede your advance and try to position accordingly. This means spreading out, flanking, and generally attempting to avoid situations where you'll need a lane since you know it will be blocked if you do.
Another way to deal with buffers is to put pressure on his caster, as this will often force him to use the buffers to defend his caster. If you're facing Lich Lord Asphyxious and he's surrounded by Caustic Mists then you're doing it right. You might not be getting him down, but he's not impeding your movements and dictating the flow of the game.
Buffers are incredibly powerful tools, and even access to a single buffer template is something that makes a caster very impressive. These are also one of the hardest tools to be up against because it mostly depends on your opponents ability to place them, and if he's good there's very little you can do about it. There are very few things you can do to counter them, and there's no easy solution to be found unless you happen to play one of the few casters that can manipulate or ignore cloud effects, in which case you have a tool against maybe half the buffers in the game.