Now that @Tiny has been appointed new chief of NCE, I would like to raise the topic of using grenades to demolish terrain, as discussed in the Attacking Terrain section of NCE. I started the discussion here, but it was too late to go into NCE 2018 by that point.
To recap, currently using Krak Grenades and Melta Bombs to demolish a structure in base contact (such as The Raid objective) is done in the HtH phase, with no roll to hit required. This has two major problems:
1) Because it is done in the HtH phase, the demolition attempt is completely silent with no chance of raising the alarm if the structure is not destroyed. Conversely, throwing a Krak grenade at the structure during the shooting phase has 83% chance of sounding the alarm, because it is a S6 'shot'.
2) With no roll to hit, there is no chance that the model runs out of grenades, or has one explode prematurely in their hand. A fighter therefore has an infinite supply of Krak grenades if they only use them on terrain in base contact.
Overall, I think it would make more sense to do demolition of structures using grenades in the shooting phase, with the same chance of raising the alarm and the same chance of running out of ammo as shooting:
To recap, currently using Krak Grenades and Melta Bombs to demolish a structure in base contact (such as The Raid objective) is done in the HtH phase, with no roll to hit required. This has two major problems:
1) Because it is done in the HtH phase, the demolition attempt is completely silent with no chance of raising the alarm if the structure is not destroyed. Conversely, throwing a Krak grenade at the structure during the shooting phase has 83% chance of sounding the alarm, because it is a S6 'shot'.
2) With no roll to hit, there is no chance that the model runs out of grenades, or has one explode prematurely in their hand. A fighter therefore has an infinite supply of Krak grenades if they only use them on terrain in base contact.
A structure can be shot at just like an enemy fighter. You must therefore roll to hit and score wounds as normal. Some structures will be easier to hit than fighters because they are large targets (+1 to hit). A Fighter in base contact with a structure can instead use Krak grenades or Melta Bombs as demolition charges. This is treated like shooting in all respects (no running or charging etc.), except the target is hit automatically. Make a roll to hit anyway to see if the they run out of ammo or the bomb explodes prematurely in the Fighter's hand.
A fighter can use Krak grenades or Melta bombs as demolition charges. The device can be placed upon a structure in base contact of the fighter during his hand-to-hand phase as long as he didn't run, charge, or shoot and isn't engaged in hand-to-hand combat. No roll is required to hit. The bomb is fastened to the structure by means of its magnetic casing, it explodes, and the target is hit automatically.