An alternative method for closing with the opponent on the table.
Many wargames are binary when it comes to deployment- you set up your toys on your side, I set up mine on my side of the table and we play out the mission.
The challenge with this deployment is the concept of critical mass.
Critical mass is where you have enough models/units on the table to generate enough dice to remove opposing models and win the mission.
Each game turn as you take losses to your units, your critical mass gets less and less, to the point where you can’t generate enough dice any more to beat the odds needed in removing opposing units.
The challenge with deploying on one side of the table is that as you move out to the mid field of the table and push forward you are exposed to shooting attacks or other unit attacks and start losing models.
Sometimes you can at least shoot/attack back, other times, depending on the theme of the army- it is is close combat/assault oriented you have to get close- taking losses on the way in to your opponent, and when you arrive, again lacking critical model mass.
Null Deployment seeks to break this, and some ruleset/units do this better compared to others.
Null deployment breaks your army up in three attack groups- each with a role, working together as a unified army.
The first group of units need to be tough- be hard to destroy/remove from the table compared to attack damage or output. They deploy in the center of your deployment zone and push forward up the center, towards the enemy every turn.
This creates pressure and incentive tactically for your opponent to castle up, keep his units together and fire on the approaching mass of center units coming at them.
This part of the Null Deployment is there to keep the opposing army in place and not moving out of the deployment zone at the start of the game.
The second group of units in your army list need to be fast moving- speed over firepower if needed. They move of the sides of the table, or if there is a way in your ruleset to come in off an alternate table edge or deployment method.
They attack from the side- “deploy” from the sides to put pressure on your opponent’s units.
The third Null Deployment group are models that can just “appear” on the table. Again, depending on the rules, maybe they teleport/summon in. Maybe the airdrop from transports, etc. They “deploy” by landing right among your opponent’s castled up units.
This attacking on all sides at once, combined with anchoring your opponent in place, allows you to hit as long and fast as you can with full critical mass of models, as opposed to moving across the table eating incoming fire for 2-3 turns.