Measuring Control to Dynamically Induce Flow in Tetris.

Dynamic Difficulty Adjustment (DDA) is a set of techniques that aim to automatically adapt the difficulty of a video game based on the player’s performance. This paper presents a methodology for DDA using ideas from the theory of flow and case-based reasoning (CBR). In essence we are looking to generate game sessions with a similar difficulty evolution to previous game sessions that have produced flow in players with a similar skill level. We propose a CBR approach to dynamically assess the player’s skill level and adapt the difficulty of the game based on the relative complexity of the last game states. We develop a DDA system for Tetris using this methodology and show, in a experiment with 40 participants, that the DDA version has a measurable impact on the perceived flow using validated questionnaires.pre-print456 K

How Fast Can We Play Tetris Greedily With Rectangular Pieces?

Consider a variant of Tetris played on a board of width $w$ and infinite height, where the pieces are axis-aligned rectangles of arbitrary integer dimensions, the pieces can only be moved before letting them drop, and a row does not disappear once it is full. Suppose we want to follow a greedy strategy: let each rectangle fall where it will end up the lowest given the current state of the board. To do so, we want a data structure which can always suggest a greedy move. In other words, we want a data structure which maintains a set of $O(n)$ rectangles, supports queries which return where to drop the rectangle, and updates which insert a rectangle dropped at a certain position and return the height of the highest point in the updated set of rectangles. We show via a reduction to the Multiphase problem [P\u{a}tra\c{s}cu, 2010] that on a board of width $w=\Theta(n)$, if the OMv conjecture [Henzinger et al., 2015] is true, then both operations cannot be supported in time $O(n^{1/2-\epsilon})$ simultaneously. The reduction also implies polynomial bounds from the 3-SUM conjecture and the APSP conjecture. On the other hand, we show that there is a data structure supporting both operations in $O(n^{1/2}\log^{3/2}n)$ time on boards of width $n^{O(1)}$, matching the lower bound up to a $n^{o(1)}$ factor.Comment: Correction of typos and other minor correction

Bayesian learning of noisy Markov decision processes

We consider the inverse reinforcement learning problem, that is, the problem of learning from, and then predicting or mimicking a controller based on state/action data. We propose a statistical model for such data, derived from the structure of a Markov decision process. Adopting a Bayesian approach to inference, we show how latent variables of the model can be estimated, and how predictions about actions can be made, in a unified framework. A new Markov chain Monte Carlo (MCMC) sampler is devised for simulation from the posterior distribution. This step includes a parameter expansion step, which is shown to be essential for good convergence properties of the MCMC sampler. As an illustration, the method is applied to learning a human controller

A Software Design Pattern Based Approach to Auto Dynamic Difficulty in Video Games

From the point of view of skill levels, reflex speeds, hand-eye coordination, tolerance for frustration, and motivations, video game players may vary drastically. Auto dynamic difficulty (ADD) in video games refers to the technique of automatically adjusting different aspects of a video game in real time, based on the player’s ability and emergence factors in order to provide the optimal experience to users from such a large demography and increase replay value. In this thesis, we describe a collection of software design patterns for enabling auto dynamic difficulty in video games. We also discuss the benefits of a design pattern based approach in terms of software quality factors and process improvements based on our experience of applying it in three different video games. Additionally, we present a semi-automatic framework to assist in applying our design pattern based approach in video games. Finally, we conducted a preliminary user study where a Post-Degree Diploma student at the University of Western Ontario applied the design pattern based approach to create ADD in two arcade style games

How to design good Tetris players

In this paper, we propose to use evolution- nary algorithms more specifically the covariance matrix adaptation evolution strategy to design artificial players for the game of Tetris. The learned strategies are among the best performing players at this time scoring several millions of lines. We also describe different mechanisms to reduce the evolution time which can be an important issue for this learning problem

Adventures of Ludom: a Videogame Geneontology

Within the last few decades, the videogame has become an important media, economic, and cultural phenomenon. Along with the phenomenon’s proliferation the aspects that constitute its identity have become more and more challenging to determine, however. The persistent surfacing of novel ludic forms continues to expand the conceptual range of ‘games’ and ‘videogames,’ which has already lead to anxious generalizations within academic as well as popular discourses. Such generalizations make it increasingly difficult to comprehend how the instances of this phenomenon actually work, which in turn generates pragmatic problems: the lack of an applicable identification of the videogame hinders its study, play, and everyday conceptualization. To counteract these problems this dissertation establishes a geneontological research methodology that enables the identification of the videogame in relation to its cultural surroundings. Videogames are theorized as ‘games,’ ‘puzzles,’ ‘stories,’ and ‘aesthetic artifacts’ (or ‘artworks’), which produces a geneontological sequence of the videogame as a singular species of culture, Artefactum ludus ludus, or ludom for short. According to this sequence, the videogame’s position as a ‘game’ in the historicized evolution of culture is mainly metaphorical, while at the same time its artifactuality, dynamic system structure, time-critical strategic input requirements and aporetically rhematic aesthetics allow it to be discovered as a conceptually stable but empirically transient uniexistential phenomenon that currently thrivesbut may soon die out.Videopeli on kasvanut edellisten vuosikymmenten aikana tärkeäksi ilmiöksi niin median, talouden, kuin kulttuurinkin näkökulmasta. Kasvun myötä ilmiön itsensä määrittäminen on kuitenkin muuttunut yhä haastavammaksi: uudet leikin ja pelaamisen muodot venyttävät jatkuvasti ’pelin’ ja ’videopelin’ käsitteitä, mikä on jo nyt johtanut kivuliaisiin yleistyksiin sekä akateemisessa että populaarissa kielenkäytössä. Kyseisten yleistysten seurauksena ne asioiden joukot, joihin ’pelit’ ja ’videopelit’ tänä päivänä viittaavat, ovat hämärtyneet äärimmäisen epäselväksi. Tämä hämärtyminen on tuonut mukanaan lukuisia käytännön ongelmia, jotka nousevat esiin ilmiöitä koskevassa tutkimuksessa, kulutuksessa, kuin myös journalistisessa käsittelyssä. Edesauttaakseen näiden ongelmien ratkaisua luettavanasi oleva väitöskirja esittelee lajiontologisen tutkimusmetodologian, joka mahdollistaa videopelin tunnistamisen suhteessa sitä ympäröiviin ja sitä muistuttaviin kulttuuri-ilmiöihin. Lajiontologista tutkimusmetodologiaa hyödyntäen väitöskirja ottaa tehtäväkseen tarkastella videopelin suhdetta neljään sitä ympäröivään tai muistuttavaan kulttuuri-ilmiöön: ’peleihin’, ’puzzleihin’, ’tarinoihin’, ja ’esteettisiin artefakteihin’ (ns. ’taideteoksiin’). Tarkastelut tuottavat videopeli-ilmiötä selittäviä aspekteja, joiden avulla sille rakennetaan alustava taksonominen identiteetti itsenäisenä kulttuurisena lajina (Artefactum ludus ludus, lyhyesti ludom). Löydetyt aspektit ja niiden mukainen taksonominen identiteetti puoltavat näkemystä siitä, että videopelin historiallinen asema ’pelinä’ on lähinnä metaforinen. Videopelin esineellisyys, dynaaminen systeemirakenne, aika-kriittiset strategiset manipulointivaatimukset sekä (aporeettisesti) remaattinen estetiikka tuntuvat sen sijaan muodostavan vankan pohjan käsitteellisesti vakaalle mutta vain hetkellisesti menestyvälle kulttuurilajityypille, joka parhaillaan kukoistaamutta saattaa pian kuolla pois.Siirretty Doriast