Most wargaming units follow a set system of how they move, shoot, and can respond on the table.
Some might be a bit more efficient, or better/worse at various phases, which is balanced out by points and army lists to use the unit. BUT, in every gaming system, either in order to create a narrative, or through just bad game design there are always units that break these rules- making it hard or impossible to counter.
An example. I’m in deep right now with Pacific Rim: Extinction, playing lots of games, and working on a BIG set of ruined city terrain to fight over.
In the movement phase of the game, moving models is *very* precise. You have a movement ruler that works with the hex base, and you can only pivot and turn the models at certain times. The rules actually do a very good job of capturing the feel that the mechs and monsters in the game are *massive* in size and move in a ponderous manner.
But this guy here above, the kaiju Hakuja has a special ability which is hard to counter- it can borrow into the ground and re-appear elsewhere. Essentially you take the model out of play, off the table, and put it back on anywhere you want.
Huge ability. So how does one counter models with game breaking abilities? Encourage the other player to use it early on when your army is at its most strongest.
On the other side, if you have such a unit, keep it alive and out of harm’s way till mid game, or when it can *truly* shift the flow of the game.
Castle up and keep you models close by, so that when the unit does use its ability, in this case while I can stop Hakuja from burrowing, I *can* hit him with everything I have- two or three jaegers when he does appear.
Make sure the opposing model gets to use the power once.