can enemy hear my step?

[brshers]

enemy will notice me before they see me?

[ThreeSon]

No, they can only detect you through sight.

[astroclat]

It seems like they know what you are doing ahead of time. Really confusing.

[brshers]

more idea?

[fumble]

In the Campaign, there are maps with special conditions.
In Multiplayer, your opponent will only see your unit if it is spotted by his troops.