In Boom Beach are there reasons to destroy all buildings?
Unlike Clash of Clans, in Boom Beach you either get all the resources or you walk away with nothing. Destruction of the Headquarters is the only thing that matters. This is the same in both PvP and PvE.
Thus, there is no loot-based benefit to destroying other buildings before hitting the HQ. If you can hit it and kill it without dying or without encountering certain defensive buildings, then you should absolutely do so. I believe some of the PvE maps are specifically laid out to teach you to exploit this.
As you've noted, you do get extra Gunboat energy for destroying buildings, so if a person or the AI has left buildings undefended, it might be worth trashing them to get some extra energy, depending on your strategy. However, that's the one and only reason for doing so.
The reasons to destroy other buildings than the HQ:
- Inflict indirect damage to the HQ (explained below)
- Get 3 points of Gunboat energy
- If it is a defensive building, it stops shooting your troops.
Indirect Damage:
HQ gets 70% damage from other buildings destruction. That means if all buildings are destroyed, HQ should have 30% health.
Source of the info: http://boombeach.wikia.com/wiki/Headquarters
- When all of the Buildings on a base except for the HQ are destroyed, the HQ will have 30% health remaining. That 70% damage is distributed evenly across all the buildings on the base, so if a base has many buildings, then each building will do less damage.
Example: A base has 10 buildings plus the HQ, so each building takes away 7% of the HQ's total health.
- The only exception is when there are 3 or fewer buildings on the base besides the HQ. In this situation, the damage that each building deals to the HQ is capped at 20%.
Example: A base has 3 buildings plus the HQ, so when those 3 buildings are destroyed, the HQ will have 40% of its health left.
These rules do apply to Outposts and Power Cores as well. Indirect damage does not damage a shield from a Shield Generator. Also, a Shield Generator does not block indirect damage.
Indirect damage is able to destroy the HQ given that the HQ has already been sufficiently damaged by direct damage.