Please help me create a new ability!

[anansethespider]

So far I've mostly tried to pick the low-hanging fruit - changes to the tech tree, units, etc. But I have an idea for an ability that I truly believe will make the game way better, and I'd really like to implement it but I don't know how.

Here's how it would work. I want to create an ability that applies to all melee-class units. I want it to make it so that if they are fortified at the beginning of a turn, they gain 1 extra movement point that turn. This way they can more effectively counter an enemy's ranged units, but only on turns where they didn't move the turn before.

Could anyone help me with some of the technical codework behind this?

 

[gyogen2]

I think that would take a requirement for unit being fortified, which is not currently in game, there is one for opponent fortified, but that wouldn't help.
This could probably be done, but not until mod tools have been released.