Pasted

// https://rathena.org/board/topic/107447-rgamble-npc/
  prontera,155,175,5	script	Sample#gambler	4_F_KAFRA9,{
 	mes "You need "+.required_item_count+" x "+getitemname( .required_item );
	if ( countitem( .required_item ) >= .required_item_count ) {
		if ( select( "Play","cancel" ) == 1 ) {
			delitem .required_item,.required_item_count;
 			if ( rand( 100 ) < .win_rate ) {
				mes "You win.";
				set .@i, rand( .reward_item_size );
				getitem .reward_item[.@i],.reward_amount[.@i];
			}
			else {
				mes "You lose.";
			}
		}
	}
	end;
 	OnInit:
		set .required_item,7227;
		set .required_item_count,10;
 		setarray .reward_item,501,502,503,504,505;
		setarray .reward_amount,1,2,3,4,5;
		set .reward_item_size,getarraysize( .required_item );
		end;
 }