C#

class LookCommand : Command
{
    public class Template : CommandTemplate
    {
        private const string NAME = "look";

        public override Command TryCreate(RpgOntologyController ontc, CommandParser input)
        {
            return MatchesCommand(ontc, NAME, input) 
                ? new LookCommand(ontc) 
                : null;
        }

        protected string CommandName
        {
            get { return NAME; }
        }
    }
    private LookCommand(RpgOntologyController controller) : base(controller)
    {
    }

    public override CommandEffect Execute()
    {
            
        StringBuilder description = new StringBuilder();
        description.AppendLine(new SceneOntologyController(Controller).CurrentSceneDescription);
        description.AppendLine();
        return new CommandEffect
                {
                    Output = description.ToString()
                };
    }
    void AppendNPC(StringBuilder build)
    {
        foreach (string npc in new NPCOntologyController(Controller).NearbyNPCs)
        {
            build.AppendLine(npc);
        }
    }
}

public Command Create(string input)
{
    // (...)

    Command cmd = null;
    var commandParser = new CommandParser(input);
    if (_templates.Any(template => (cmd = template.TryCreate(_controller, commandParser)) != null))
    {
        return cmd;
    }

    throw new ArgumentException("Invalid command.");
}