As of late I've been playing a good mix of games and since the lockdown I've been playing more games at home. At home I have a 6' by 4' board, I know that nowadays 40k is supposed to be played on a smaller board size but this is a minimum and I especially find 2000pt games played with a 'hoard' style army to be very limiting on a min board size.
But one thing I have started to notice is that I'm starting to need certain types of terrain depending on my board size.
Some of the larger buildings that I use in the big games really don't work well on smaller boards. The 'area' terrain effect is lessened when the board is downsized dramatically. Thankfully my terrain is not affixed to a base and I use some old game boards to represent the area that the terrain occupies. This allows me to change and adjust the majority of my terrain.
But why is having smaller footprints important with different board sizes?
The ability to block lines of sight in 9th edition is extremely important as shooting can be overwhelmingly powerful. Large area terrain pieces on smaller boards can limit this as single moves can bring you into LOS (Line of Sight). On smaller boards this is where I would use my smaller base pieces to create MORE block's that can be used to completely block off more lines of sight. This will change your game when playing on those smaller boards.
A shows two large ruins on a 44" by 30" board. As you can see on the second picture one move is all thats needed to bring both units within LOS of each other, making those that get the second turn biased.
B shows that by breaking the two large ruins into 4 smaller ones you get a lot more tactical options in smaller games.
When you get even smaller (such as kill team) then boards for your terrain pieces become less important. You need to start using more scatter terrain with some possible platforms that can give you elevation because of the way the game plays. This can actually cause a problem for people that play multiple game types with 28mm figures.
A persons collection of terrain can be determined by the main game they like to play at home. If most of your games end up being 40k then you will find yourself with more ruins and possible tree like pieces of terrain then you would with what you call 'scatter' terrain.
Scatter terrain can be things like small barricades, stacks of barrels, small crates and other terrain pieces that wouldn't really make much difference to a larger game like 40k, but can be incredibly important when playing smaller skirmish games where individual models rather than units become the mode of play.
We all know terrain is just as important as the models we play with. A fully painted army played on a table with some good looking terrain will always improve our enjoyment of the game, but incorrect terrain types can ruin the game also. So remember, the smaller the board the smaller the terrain pieces need to be.