RunicBoard.RemoveAllRunesFromThisTurn C# (CSharp) Method

    public void RemoveAllRunesFromThisTurn()
    {
        List<int> markedToDelete = new List<int>();
        foreach (KeyValuePair<int, Rune> kvp in _runesOnBoard)
        {
            if (kvp.Value.TurnUsed == ClientManager.GetInstance()._client._turnNumber)
                markedToDelete.Add(kvp.Key);
        }

        for (int i = 0; i < markedToDelete.Count; i++)
        {
            _runesOnBoard.Remove(markedToDelete[i]);
        }

        if(_runesOnBoard.Count < 2)
        {
            SecondPlaced = -1;
        }
    }