Played three games of 8th now, and I use Earthshakers and (in bigger games) Colossus Bombards. There seem to be a couple of issues with explosive weapons - those that used to use blast templates. Disclaimer: I'm glad to see the back of blast templates as they were clunky, slowed the game down, caused disagreements, exacerbated climate change, funded terrorism, etc.

Basically, explosive weapons don't work at the moment. Let me lay out why:

Previously, the larger and more packed a unit (or army) was, the more likely it was to take hits from blast templates. Nearby units were also at risk. Scatter was mitigated by BS, allowing a realism of the gunner's skill. Higher density of models meant more were hit. The response was for horde players to spend hours spacing their models 2" apart: obviously we can't go back to that and 8th is overall great because it's smoother and faster. An important note here is that generally people *didn't want* to string out their large units as it lowered their impact and obstructed the army (as well as making gaming miserable).

BUT in 8th edition higher-model-count-unit armies now have a degree of immunity to damage. Previously, if you took a high model-count army, you had a choice: either take more damage from explosions or suffer tactically from careful spacing and movement. This is reflected in reality because a more spaced-out horde will have less impact when it gets into close combat and a tightly packed one is more vulnerable to explosions; all of this translated well into the game mechanics. However, in 8th edition the physics of explosions are frozen at a low-model-count level. There is a vacuum in the realm of higher model-count armies: they're neither more vulnerable to explosions nor have any penalty for moving to counter them (real or imagined).

In other words, there is now a direct link between higher model count and greater chance of success, which conflicts with the points/Power Level system that makes a higher model count army have less-powerful models than a lower count one.

On the flip side we have the opposite problem: explosive weapons get their full number of 'shots' against single-model units. Against vehicles I can understand this due to the target's size (although I'm uncomfortable with an Earthshaker cannon seeming to be the go-to tank sniper weapon in my army)... but against a lone character it makes no sense. The DX shots has clearly been used as a way to translate the randomness of Blast template hits (i.e. the blast radius covering more *models*) into something faster and easier, but this doesn't work with a lone character. They would previously have only taken one hit from the template; now they take everyone's hits. I'm aware that characters are protected by screening to an extent but undoing this protection through error or tactics should not result in negation of the laws of physics.

So here's what I propose, and this probably needs a bit of wiggling:

-Against characters with fewer than 10 wounds, an explosive weapon is limited to 1 shot. The damage factor (eg. Earthshaker D3) is sufficient to describe the impact
-Against vehicles, explosive weapons may only ever get their stated number of shots (eg. Battlecannon D6 shots)
-If targeting any other unit, for every 5 models in the unit (ignoring the first 5) you add 1 extra dice to the number of shots, up to a maximum of 3 extra dice. Eg.:
Battlecannon firing at unit of 1-9 models: D6 shots
Battlecannon firing at unit of 10-14 models: 2D6 shots
Battlecannon firing at unit of 15-19 models: 3D6 shots
Battlecannon firing at unit of 20+ models: 4D6 shots
(Bear in mind that those shots still need to roll to hit. So a Battlecannon against a 20-strong unit will still only get an average of 7 hits - perfectly reasonable for a large, more densely-packed unit)

To expand on the logic a little, spacing is still used as a mechanic for determining success in 8th edition. For example: spaced out with lots of guns increases likelihood of some models not being in range of a central target; spaced out and charging increases likelihood of some models not getting into Fight range. As stated above, players are no longer required to space their models because of blast templates, however this means there is a 'hole' in the spacing mechanism in the form of explosions actually shrinking in relation to the size of the target unit. If the spacing mechanism is altered for larger units in terms of taking fire, the realism of firing explosions into them must change correspondingly.

As for increasing the number of shots to correspond to the size of the target unit, there is already a precedent in the rules: certain guns do exactly this. My experience is limited to Chaos and Astra Mil units but of those:
-Leviathan Dreadnought grav thingy rolls more dice for larger target units
-demolisher cannon switches from D3 to D6 against units >5 models
-Fellblade cannon gets reroll on number of shots against units of >5

So there you have it. Thoughts and experiences?