Scoring matches of a game - reducing duplicated code
You could put the statuses into a constant array and use the index variable to fetch them out:  

void BlockParty::on_comboBox_currentIndexChanged(int index, Score* score)
{
  static const BlockPartyLogic value_table[] =
  {
    BlockPartyLogic::RAMP_OFF,      // Index 0
    BlockPartyLogic::RAMP_PARTIAL,  // Index 1
    BlockPartyLogic::RAMP_COMPLETE, // Index 2
  };
  if (index &lt; sizeof(value_table) / sizeof(value_table[0]))
  {
    score-&gt;ramp_position_A = value_table[index];
  }
    score-&gt;update_internals();
}


If you want to select functionality based on an index you could use a static const array of function pointers or function objects.