Paradox Interactive have detailed some of the new features in By Blood Alone, the next expansion pack for Hearts of Iron IV.

Hearts of Iron IV: By Blood Alone features new focus trees for Italy, Ethiopia, and Switzerland, giving each nation new mechanics and events. The expansion also features a new aircraft designer system.

You can see some of these mechanics detailed in the dev diary below:

You can find a rundown (via Steam) below:

Build a new empire, resist foreign aggression or explore the limits of neutrality in Hearts of Iron IV: By Blood Alone. This new expansion for Paradox Interactive’s World War II grand strategy wargame adds new alternate history options and gameplay variety for three nations, as well as other significant changes.

Features of Hearts of Iron IV: By Blood Alone include:

• New Italian Focus Tree:
  Follow the historical path of Mussolini’s Italy or rewrite history by restoring power to the monarchy, leading a Communist revolution or promoting democracy.
• New Ethiopian Focus Tree:
  Defy the odds to defeat the Italian invader or resist the conqueror from abroad using unique Government in Exile abilities.
• New Swiss Focus Tree:
  Surrounded by France, Germany and Italy, the mountain nation of Switzerland finds strength in its neutrality, balancing competing factions and overtures from the great powers.
• New Peace Conference Options:
  Demilitarize zones of the map or entire nations, bid on the capital ships of defeated powers, or claim control of enemy resources or factories as reparations.
• Aircraft Designer:
  Design and build your own planes, from nimble interceptors that prioritize speed to durable bombers crafted to unload tons of destruction from high above.
• Unit Medals:
  A log of each division’s accomplishments lets you track their performance, and even allows you to award unique medals to division commanders for their actions in the field.
• Embargo Interaction:
  Embargo your enemies with a new diplomatic interaction, preventing them from trading with you if they have generated enough world tension.
• New Unit Models:
  Over 20 new unit models for Italy, Ethiopia, and Switzerland
• New Plane Models:
  67 new plane models
• 12 New Music Tracks

Hearts of Iron IV has been available on Windows PC, Linux, and Mac (all via Steam).