Sorry, but Blizzard close access to D4 forum for those who did not pre-purchase. So I need to post here. 
Barbarian skill “Bash” can using with one-handed or two-handed weapon.
How can I use it with one-handed ? I have to take off two-handed weapons in inventory for it ? It seems like it always use two-handed weapon for this skill.
How “Lucky Hit” works ? I’m absolutely do not understand.
Lucky Hit: Up to +X% Chance to Execute Injured Non-Elites. This means that every time you hit an enemy you have a chance to immediately kill it . In Diablo 4 there’s a bunch of random on-hit effects you can trigger with any attack, which are called Lucky Hits. Lucky Hits come from many different sources: skills, passives, items, and Legendary Aspects. - Reddit
So it’s basically a useless affix on a weapon or item which could be replaced by something better for perm dmg or what? Or you need to find all the items to make it proc on every hit i guess… le sigh.
If you do not have a 2 handed weapon equipped, you will get the one handed effect of Bash.
The game uses a system where it will auto-swap to the best weapon to perform a skill, which given that Barbarian has skills that simply do more with a 2 handed weapon, will mean it will swap to a 2 handed weapon.
Lucky Hit is simply a chance to have an effect activate upon hitting an enemy. It’s functionally the same as D3’s “Chance on attack/hit” things just it can be affected by the Bonus Lucky Hit Chance stat to increase the odds of it occuring.
kinda op…
Thank’s all for reply! 
Unless you specifically assign a weapon the system will auto select a weapon. While looking at the skill (Bash) hold the middle mouse button and it will change to one of the specific weapon types, continue to hold/click the middle mouse button until the 1 handed option shows selected. Note regular click will not work, you must hold it long enough for the selection to change each time. You will see at the bottom of the skill window will change from “autoselected” to “two handed slashing”, etc.
To swap the type of weapon used go to the skill where you see what weapon it uses then center click to switch to a different type of weapon.
How did anyone even find out about crap like that? There was no direct mention that I saw about setting specific weapons to skills?
I just assumed they automatically swapped due to requirements of the skill. lol
Good lord. What else has been hidden behind special clicks that I missed?
It was bugging me when I played it, so I had to figured it out for myself.
Barbs have the unique ability to equip 4 Weapons. And thus benefits from 4 Legendary Powers.
D4 Barbs are like you playing D3 with 6 Legendary Gems equipped whereas others are playing with only 3, 4 or 5 Legendary Gems. It is true that Beta Barbs were meh, but once more powerful Legendary Aspects become available, they will become OP!
I might be wrong, but each skill you use has it’s own weapon class. I don’t know about assigning weapons into the skill slots.
from what i’ve played, you can only use a skill that uses the correct weapon for the skill.
for example:
leap attack (or whatever its called) will only use your two handed weapons.
doubles swing, or dual something, will only use your one handed weapons.
according to the skill you use.
TL:DR
skill = weapon class = what weapon will be used.
you can’t use a skill if it doesn’t match the weapon class.
Keyword: Injured. The non-elite enemy has to be under 35% health.