Na'an

Na’an

Difficulty: 🎄🎄
Shifty McShuffles is hustling cards on Film Noir Island. Outwit that meddling elf and win!

Hints

Stump the Chump

From: Shifty McShuffles Try to outsmart Shifty by sending him an error he may not understand.

The Upper Hand

From: Shifty McShuffles Shifty said his deck of cards is made with Python. Surely there’s a weakness to give you the upper hand in his game.

Solution

When playing it always results in ties but it is possible to observe that NaN can be used instead of a number but the game logic prevents having more than one card set to the same value, including NaN. Analyzing the JS code, I identified the ajax call sending the values of the cards:

$.ajax({
    type: "POST",
    contentType: "application/json",
    dataType: "json",
    async: true,
    url: `action?id=${rid}`,
    data: JSON.stringify({ 'score': '' }),
    complete: function (data) {
        var response = JSON5.parse(data.responseText)
        if (response.request === true) {
            if (response.data.conduit) {
                __POST_RESULTS__(response.data.conduit)
            }
            ShiftyElfScoreToast.showMessage("Shifty's Score: " + response.data.shifty_score + ' ')
            PlayerScoreToast.showMessage("Player's Score: " + response.data.player_score) 
            win_lose_score_message(response.data.score_message, response.data.win_lose_tie_na)
        } else if (response.data) {
            Talk(response.data)
        }
    }
});

Using the developer tools console to alter the data being sent, it is possible to send all NaN, resulting in Shifty to lose:

{"data":{"maxItem":{"num":NaN,"owner":"p"},"minItem":{"num":NaN,"owner":"p"},"play_message":"Darn, how did I lose that hand!","player_cards":[{"num":NaN,"owner":"p"},{"num":NaN,"owner":"p"},{"num":NaN,"owner":"p"},{"num":NaN,"owner":"p"},{"num":NaN,"owner":"p"}],"player_score":6,"score_message":"","shifty_score":4,"shiftys_cards":[{"num":0.0,"owner":"s"},{"num":9.0,"owner":"s"}],"win_lose_tie_na":"n"},"request":true}

It is enough to do it once, as then all other games will be a tie, thus resulting in a player’s win.