Scatter: or How I Learned to Stop Worrying and Love Deepstrike

Deep strike is scary, that's for sure. You bring a unit in but there's a chance of the unit being deployed, placed somewhere completely useless, or not arriving for another turn. Granted some armies make Deep Strike even worse but if you're fortunate enough to not have to deal with those issues, Deep Strike can make a glorious entrance.

The Odds: To Hit or Not to Hit
There is, roughly, a one in three chance of landing spot on to your target and a two-thirds chance of "scattering" in one of 360 degrees worth of drift. This means that - by the numbers - you're most likely to drift some distance away.

While this is fairly random, you do have the ability to guess just how far you'll drift. We'll come back to this latter.

The Odds: So Close...
We've established that we're likely to NOT land where we want we have to figure out just how far we're going to drift.

% Chance of Results on 2D6

Dice Result	Exact Roll	Less Than or Equal To	Greater Than or Equal To
2	2.77%	2.77%	100%
3	5.55%	8.33%	97.22%
4	8.33%	16.66%	91.66%
5	11.11%	27.77%	83.33%
6	13.88%	41.66%	72.22%
7	16.66%	58.33%	58.33%
8	13.88%	72.22%	41.66%
9	11.11%	83.33%	27.77%
10	8.33%	91.66%	16.66%
11	5.55%	97.22%	8.33%
12	2.77%	100%	2.77%

What this essentially means to us in terms of Deep Striking is that we have the highest odds of drifting 7" away from our intended landing zone and a little over a 41% chance of drifting over 8" away.

The Landing
This is how I've begun to calculate my drift: First I calculate the "fire" range of my deep-striking unit: I subtract 8 from the range of the weapons on the unit I want to fire and call this my "effective range" for the deep strike. Then I look for the Landing Zone. A Landing Zone will be approximately 12-14" of mostly clear or at the very least just has no models or impassible terrain. Models, impassible, and/or table edges reduce my odds of a good landing.

Landing Zones are then evaluated by the following criteria:

• Targets of Opportunity: How many critical targets are there within the effective range of that unit"? How many targets that I can hit - period - are there near that landing zone?
  
• Targets of Reach: On the next turn, are there any units I can reach once I can move?
• Safety of Landing Zone: How safe is that zone as I drift from it? Will I come under heavy fire? Do I run into a chance for a mishap or a Dangerous Terrain test?

The way I factor this is by a Safety Estimate. Simply draw an imaginary line between your preferred target and extending directly back from your model, then reduce the line to approximately 7" in both directions from your model. This is your forward/rear axis. Bisect that line across your model with another 7" line to create a left/right axis. Since you have only a 2/3 chance of drifting at all and a 25% chance of drifting into any of these quadrants you then have only a 16% chance of drifting into any given quadrant. That means that if your left-rear quadrant is filled with enemies you - in reality - have roughly only a 16.6% chance of landing in them. If you're deep striking right by the table edge you have roughly a 33% chance of drifting off that edge. Not as bad of odds, now is it?

Tripping the Drift
Now we've drifted and, with luck, no more than 7" away from my original target. If you drifted towards your opponent you're likely in a better range. Drifts that are covered by the front half of your axis are still likely to leave you in a decent range of your opponent. If you drift away you may still have a chance, but at the very least you will have to move and shoot next turn.