By adding new racial trait for all races, except 1 race, I think.
IE, Trait: General Race Ship Construction.
Then add this trait as second tech req for all designs except those that you want to have access with your race:
Name := Escort
...
Number of Tech Req := 2
Tech Area Req 1 := Ship Construction
Tech Level Req 1 := 1
Tech Area Req 2 := General Race Ship Construction
Tech Level Req 2 := 1
...
but
Name := Cruiser
...
Number of Tech Req := 1
Tech Area Req 1 := Ship Construction
Tech Level Req 1 := 5
...
Then edit AI_general files for all races (except the one with limited ship access) to add this new trait and make new EMPs.
Edit: huh, typing too slowly and refreshing page too rarely
[ May 14, 2004, 21:05: Message edited by: aiken ]