In my opinion this forum is designed for players to share ideas to enhance their gaming experience. You can take someone’s idea or leave it; the choice is yours. With that said there are people who want to add elements to the game that have a historical foundation like paratroopers.
I’ve been playing Axis since the 80’s and have used plenty of expansions, and house rules. I personally like having the paratrooper option and have used them for years. Not sure if it was Xeno or Gamers Paradise that first turned me on to the idea. Over the years I’ve come to use the following rules.
Only the major powers are allowed to build paratroopers. It is not a tech and can be purchased as early as the first turn.
Paratroopers cost 1 extra IPC to convert an infantry. Max of 4 paratroopers in play at any time. Once converted to a paratrooper it will remain so until destroyed.
I’ve used both bombers and air transports to deploy the units. In either case the paratrooper and the air unit must begin the turn from the same territory. Also each plane can only carry 1 paratrooper.
For air transports we use a cost: 12, move: 4, attack: N/A, defense: 1 (D6), 2 (D12), 3 (D20). Air transports can also carry 2 infantry during the non-combat movement phase. Starting set-up for air transports: Germany 2, Britain 1, Japan 1, Russia 0, US 1.
The biggest issue with adding new rules & ideas is maintaining game balance. I don’t feel like using paratrooper this way is unbalancing at all.