4403,Kiel_Card,Kiel-D-01 Card,6,20,,10,,,,,,,,769,,,,,{ if(isequippedcnt(4403) == 1){bonus bDelayRate,-30;} },{ if(isequippedcnt(4403) > 1){ message strcharinfo(0),"You can only equip 1x "+getitemname(4403)+"! Additional card(s) has been disabled."; } },{}
What this does:
Effect only activates if there is one card equipped.
If more than one card is equipped, a notice will pop up for the user notifying them that other cards will have no effect.
Note:
Please test, this is untested. Also to anyone who is better at coding than me, please enlighten us if this would work or not xD