Battleground

Frontline:

You can Attack the enemy: Backline,Frontline and Cover.
You can be Attacked by the enemy: Backline, Frontline, and Cover.

You can be damaged by Any attack types.
You can use Any attack types.

Rush

If the enemy Frontline is empty you may force any single creature to move to the frontline on your turn for free.

Backline:

You can Attack the enemy: Backline and Frontline.
You can be Attacked by the enemy: Backline.

You cannot be damaged by attacks with Meele.
You cannot attack with Meele.

Barrage

You may remove an enemy creature of their choice from Cover (represents destroying it) as an action. The creature removed choses the front line or back line to "retreat". The next Action on moved creatures turn cannot be the Movement action.

Cover:

You can attack the enemy: Frontline.
You can be Attacked by the enemy: Frontline.

You cannot be damaged by attacks with Ranged.
You cannot attack with Ranged.

Ambush

As an Action, you may move yourself to the frontline then make a Ranged or Melee attack as part of the same action.

X	Frontline	Backline	Cover
Can Attack	Frontline, CoverO	Frontline, BacklineO	FrontlineR
Can be Attacked by	Frontline, Backline, CoverR	BacklineG	FrontlineG
You cannot attack with	None G	Melee O	Ranged O
You cannot be attacked by	None R	Melee O	Ranged O
Ability	Rush Need G ability	Barrage need R ability	Ambush Need O ability

Flying you are considered to be in the backline and ignore movement effects. If you engage in melee, you are no longer flying and are placed on the frontline.