New spawn extension system

The extension system in the game has been changed. We decided to do away with the notion of the creep's body parts number and instead introduce the limit of the total amount of energy to be used for building in a room – in the spawn and all extensions together.
While previously a spawn with no extensions could generate up to 5 body parts, now it can contain up to 300 energy units and create creeps using this amount of energy. All extra cost above this limit must be available in the extensions at the moment of the beginning of the creep spawning. Besides, capacity of each extension is decreased to 50 energy units.
It's important that energy for extra cost is taken only from the extensions, but not the spawn! The spawn never consumes more than 300 energy units, even for expensive creeps.
Here are a few examples of various creep configurations costs before and now:
Body Before Now
Spawn Extensions Total Spawn Extensions Total
CCCCM 250 energy  — 250 energy 250 energy  — 250 energy
CCCCMMMM 400 energy 600 energy
3 extensions
1000 energy 300 energy 100
2 extensions
400 energy
RRRRRAAAAAMMMMM 1400 energy 2000 energy
10 extensions
3400 energy 300 energy 1100
22 extensions
1400 energy
The number of extensions available for building extensions is also increased at all RCL levels. See more in Territory control.
This new system should significantly simplify building of high-level creeps, which means that overall you will need less creeps for the same tasks and less CPU for controlling them. However, for quick building of expensive creeps, you will need to set up an effective energy transport scheme in many extensions. It will surely become an interesting task on programming room work.