How to make a tower not damage a certain unit type

[nokiaman]

So i would like to make a certain unit type Immune to a Towers basic Attack, and Slow Poison ability.

But my brain is exploding whenever i get close to the solution so i figured its better to ask here

 

[Nichilus]

You could give that certain unit-type a specific unit classification.
For example give those units "Ancient" classification and make your tower's basic attacks and slow poison target only "Non-Ancient".

 

[RobertMKD]

You can also make them magic immune, so towers using magic won't attack them (but you can change that easily, if u want)

 

[nokiaman]

Thank you Nichilius, that was so obvious and now i fell so stupid

 

[PublishedShadow]

Another solution is to give the units Divine Armor. Only Chaos damage can deal damage to Divine Armor. I can't remember if a non-chaos unit can target a divine armored unit or not though.

While classification is one way to do it, this is another option in case you need additional specialized units.