Turn 0 Artillery Bombardments

[scorpio_rocks]

It depends on the type of battle:
(From the game guide V7 2013 Patch Upgrades:

Artillery can no longer be plotted (including air transports and spotters) on turn 0, or 1 if the battle is a meeting engagement or you are the delayer or defender. A scenario designer can still plot artillery as he desires in his scenario, however. The AI may still plot fire as before. This is deliberate to penalise a human player who packs the approach roads. Note that the bombardment screen may still be entered to plot FDF gold spots, or toggle the blast radius display. The arty units just will not show up till post turn 1 if unavailable in the scenario for pre-game bombardment

So as a player in a non-scenario battle you can ONLY plot a pre-game bombardment if you are the Attacker in an Assault or Attack battle type.