var resources[3] = { 0, 0, 0 };

#define lifetime skill1  // helper skill
#define id skill2  // type of the resource
#define amount skill3  // amount of the resource

#define wood 0
#define stone 1
#define ore 2

function resource_event()
{
  resources[my.id] += my.amount;
  my.lifetime = 0;
}

action resource_act
{
  my.emask |= (ENABLE_ENTITY | ENABLE_IMPACT);
  my.event = resource_event;

  my.lifetime = 1;
  while(my.lifetime) { wait(1); }

  wait(1);
  ent_remove(me);
}