How to make a hero limit

[mr.gnome]

I want a hero limit like 1 hero per player how can i do this and if a player has a hero they cant load

 

[Just_Spectating]

Advanced --> Gameplay Constants

 

[qbrtux]

I want a hero limit like 1 hero per player how can i do this and if a player has a hero they cant load

Do you mean like summoning a hero from an Altar or having a lot of heroes with circles of power that a unit have to enter or blahblahblah, can you explain your problem a bit more, please?