what are the -leadership item for dwarves and driods
 

This is mainly for a droid army, ( 2 repair droid stacks 1 guard droid) as they are counted as dwarves?

Engineers badge is -20% for droid leadership.

There's a sword that decreases dwarf leadership requirements. Is that the elemental sword? What it's leadership reduction?

Anything else that gives special leadership bonuses/ leadership reductions to droids/dwarf?

edit : How does the steam armor help ? and does the telescopic lens help repair droid (+100% attack)

Yes, droids are dwarves.

Royal Hammer: weapon, +5 attack, -15% leadership for dwarves
Horn of King Borg: artifact, +5 attack for dwarves, -10% leadership for dwarves, -1 initiative for allied humans and elves
Axe of Ice: +7 defense, repair droid's melee attack becomes no retaliation, +10% physical damage resistance for dwarves
Axe of the Wind: +5 attack, +1 speed and initiative for dwarves


Steam armor adds 30% to a unit's base attack and defense at the cost of 1 speed. So +3 attack and +7 or +8 defense for repair droids. +7 or +8 attack and defense for guard droids. As far as I know the "affects short humanoid warriors" is just for flavor and doesn't actually mean anything, I could be wrong though. No idea on the lens. There are several categories of "archers" with no real rhyme or reason as to what units benefit from the "archer" requirement on a spell or skill or piece of equipment. Someone else probably knows this simply through trial and error.

Steam Armor:

testet it a bit.

Tall units don´t get any bonus like

Dragons, Ents, Arch-Demons, Cyclops, Giants. It appeares, that no level 5-unit can benefit from the bonus of this armor (and the penalty of course)

So Steam Armor isn't limited to dwarves then?

No, my inquis, palas, shamis, archmages hava had a profit from this item

I suppose not affecting the really powerful units makes sense. Adding 21 attack/defense to a black dragon, while not always useful, would be pretty nuts for one equipment slot.

Testing things first before talking about them would probably have been a good idea as steam armor doesn't affect droids, doh! The question then becomes, what is or isn't a short humanoid warrior? Black knights are affected, but I wouldn't consider them short except in comparison to dragons and the like.