Hi!
I'm making a game about steal value("flags"), and I wanted to make a leaderboard about how much flags players have.

Since other players can steal you your "flags" I need to update that leaderboard evend with lower "scores". But for now my leaderboard only update when I submit a higher score.

I wonder if there's any way to use leaderboard this way, if not I would have to somehow compare all players flags and order them, but I dont know if it would be very efficient :/

Great! That make it!
Just one more little question, how can player A submit a score for player B?

So when A steal from B I want to submit for both, I'm trying this using the player B ID:

var targetID = Spark.getData().targetID;
if (targetID == 0)
    {
    targetID = Spark.getPlayer().getPlayerId();
    }
    
//Also get the new data to be saved
var flagsAmount = Spark.getData().flagsAmount;

//Load the collection where data is stored
var targetData = Spark.runtimeCollection("targetData"); 

//Construct a data collection with the new data to replace the first one(or create it if it does not exist)
var currentPlayer =
    {
    "flagsAmount": flagsAmount
    }
    
targetData.update
    (
        {
        "playerID": targetID
        }, //Looks for a doc with the id of the current player
        
        {
        "$set": currentPlayer
        }, // Uses the $set mongo modifier to set old player data to the current player data
        
        true, // Create the document if it does not exist (upsert)
        false // This query will only affect a single object (multi)
    );

 It changes player B flags value, but in the leaderboard only change for player A

Work like charm! Thanks a lot Liam!

In case anyone can find it usefull this is what I did to steal "score" from the leaderboard:  

//First Get target ID 
var targetID = Spark.getData().targetID;
//Also get the new data to be saved
var flagsAmount = Spark.getData().flagsAmount;
 
var request = new SparkRequests.LogEventRequest();
request.eventKey = "LaderboardFlags";
//request.targetID = targetID;
request.totalFlags = -flagsAmount;
 
//playerID here being the player you want to subtract the amount from
var response = request.SendAs(targetID)
 
var playerID = Spark.getPlayer().getPlayerId();
var request = new SparkRequests.LogEventRequest();
request.eventKey = "LaderboardFlags";
//request.targetID = targetID;
request.totalFlags = flagsAmount;

var response = request.SendAs(playerID)

  So I call "StealFlags" and set a target ID and a flags amount and thats reduced from target and added to the player :D