Super Mario Bros. is Harder/Easier Than We Thought

Mario is back! In this sequel, we prove that solving a generalized level of Super Mario Bros. is PSPACE-complete, strengthening the previous NP-hardness result (FUN 2014). Both our PSPACE-hardness and the previous NP-hardness use levels of arbitrary dimensions and require either arbitrarily large screens or a game engine that remembers the state of off-screen sprites. We also analyze the complexity of the less general case where the screen size is constant, the number of on-screen sprites is constant, and the game engine forgets the state of everything substantially off-screen, as in most, if not all, Super Mario Bros. video games. In this case we prove that the game is solvable in polynomial time, assuming levels are explicitly encoded; on the other hand, if levels can be represented using run-length encoding, then the problem is weakly NP-hard (even if levels have only constant height, as in the video games). All of our hardness proofs are also resilient to known glitches in Super Mario Bros., unlike the previous NP-hardness proof

Press A to Retry: Teaching and Motivating Players Through Failure in Difficult Games

As video games have gained greater mainstream popularity over the last couple decades, the utility of difficulty and failure in games has shifted. In an effort to create games that are accessible to an ever-increasing population of potential customers, games have trended toward lower difficulty to accommodate new players. In response to this, independent designers have created games that return to the harsh difficulty of the arcade and console games of the 1980s which also include mechanics that maintain mainstream accessibility through alternative failure punishments. This thesis analyzes the design of commercially successful hyper-difficult games to determine how their mechanics foster player motivation and learning in the face of repeated failure. Ultimately, this thesis asks if the ways in which difficult games mobilize failure to educate and motivate could be applied to other systems and to what ends

Measuring Difficulty in Platform Videogames

Automatic generation of game levels improves replayability and also allows content adaptation. One important aspect to take into account in the creation of any videogame is difficulty, in particular when it is possible to adapt content. However, defining difficulty is not a straight subject. In this paper we propose a metric for game difficulty in platform levels, mostly based on users’ losing probability for each obstacle. This metric can be further used in automated processes that generate levels for this type of games, helping the process to recognize whether a level is suitable or not for a certain player. We also present some examples of the usage of this metric in commercial games

Analysis and application of rhythm in the design of 2D platformer levels

Abstract. The video game industry has grown quickly from its humble beginnings to one of the largest entertainment industries in the world. Fuelled by the continuous advancements in technology, the quality and quantity of content in AAA video games continues to rise along with customer expectations. But with the ever-higher ambitions, the development budgets and durations rise with them, making the cycle unsustainable on the long run. Procedural content generation is a technique that has the potential of helping break the cycle. The automatic generation of game content, such as levels, could help game developers reach the desired quantity of content with a fraction of the time and money required. However, commercial applications of procedural content generation so far have been largely limited in scope and lacking in quality, with the more successful cases being found in smaller budget indie games. In this study, the possibility to use the idea of rhythm in guiding procedural level generation towards better quality was studied. Using a design science research approach, the gameplay rhythm of original Super Mario Bros. levels was extracted and used to build a rhythm-based procedural 2D platformer level generator. The nature of the generated levels was investigated by computational metrics, and the quality of them was evaluated by a series of playtests. It was found that the existing platformer levels included an extractable rhythm. The rhythm-based level generator that was built upon the found rhythm data produced levels that were closely on par with the original levels, indicating that rhythm has potential applications in informing how a procedural content generator could create more meaningful and higher quality content. Finally, this experimental approach in incorporating music theory to procedural content generation opens up many interesting new avenues for future research

A computational model for generating visually pleasing video game maps

In this work we introduce a computational model based on theories of graphical design to generate visually pleasing video game maps. We cast the problem of map generation as an optimization problem and prove it to be computationally hard. Then, we propose a heuristic search approach to solve the map generation problem and use it to generate levels of a clone of Super Mario Bros (SMB) called Infinite Mario Bros (IMB). Before evaluating the levels of IMB generated by our system, we perform a detailed study of the approaches commonly used to evaluate the content generated by computer programs. The evaluation used in previous works often relies on computational metrics. While these metrics are important for an initial exploratory evaluation of the content generated, it is not clear whether they are able to capture the player’s perception of the content generated. In this work we compare the insights gained from a user study with IMB levels generated by different systems with the insights gained from analyzing computational metric values. Our results suggest that current computational metrics should not be used in lieu of user studies for evaluating content generated by computer programs. Using the insights gained in our previous experiment, we performed another user study to evaluate the IMB levels generated by our method. The results show the advantage of our method over other approaches in terms of visual aesthetics and enjoyment. Finally, we performed one last user study that showed that our method is able to generate IMB levels with striking similarity to SMB levels created by professional designers.Neste trabalho apresentamos um modelo computacional baseado em teorias de design para gerar mapas de jogos de plataforma visualmente agradáveis. Nós estudamos o problema de geração de mapas como um problema de otimização e provamos que uma versão simplificada do problema é computacionalmente difícil. Em seguida, propomos uma abordagem de busca heurística para resolver o problema de geração de mapas e utilizamos ela para gerar níveis de um clone do Super Mario Bros (SMB), chamado Infinite Mario Bros (IMB). Antes de avaliar os níveis de IMB gerados pelo nosso sistema, realizamos um estudo detalhado das abordagens comumente utilizadas para avaliar o conteúdo gerado por programas de computador. A avaliação utilizada em trabalhos anteriores utiliza apenas métricas computacionais. Embora esses indicadores são importantes para uma avaliação inicial e exploratória do conteúdo gerado, não é claro se são capazes de capturar a percepção do jogador sobre o conteúdo gerado. Neste trabalho, comparamos os conhecimentos adquiridos a partir de um estudo com seres humanos usando níveis de IMB gerados por diferentes sistemas, com os conhecimentos adquiridos a partir de análise dos valores de métricas computacionais. Os nossos resultados sugerem que as m ́etricas computacionais atuais não devem substituir estudos com seres humanos para avaliar o conteúdo gerado por programas de computador. Usando os conhecimentos adquiridos em nosso experimento anterior, foi realizado outro estudo com seres humanos para avaliar os níveis de IMB gerados pelo nosso método. Os resultados mostram a vantagem do nosso método em relação a outras abordagens em termos de estética visual e diversão. Finalmente, foi realizado outro estudo com seres humanos, mostrando que o nosso método é capaz de gerar níveis de IMB semelhantes aos níveis de SMB criados por designers profissionais.Coordenação de Aperfeiçoamento de Pessoal de Nível Superio

Attack on the clones: managing player perceptions of visual variety and believability in video game crowds

Crowds of non-player characters are increasingly common in contemporary video games. It is often the case that individual models are re-used, lowering visual variety in the crowd and potentially affecting realism and believability. This paper explores a number of approaches to increase visual diversity in large game crowds, and discusses a procedural solution for generating diverse non-player character models. This is evaluated using mixed methods, including a “clone spotting” activity and measurement of impact on computational overheads, in order to present a multi-faceted and adjustable solution to increase believability and variety in video game crowds

The rebirth of U.S. console gaming: A historical comparison of Nintendo versus Sega 1983–2001

This master’s thesis examines the rival videogame companies Nintendo and Sega in the “console wars” of the 80s and 90s, and how they developed. After Atari brought home consoles into consumer consciousness, the market crashed and was picked back up by Nintendo who revitalized the industry. The ensuing battle between Nintendo and Sega spanned two decades. Gaming history is still in its infancy, struggling with a veneer of illegitimacy, but this rivalry has been a hot area of study by gaming historians. It is clear today that Nintendo survived this war while Sega had to bail out, but only some earlier research has gone in-depth in trying to find some of the underlying intricacies as to how this happened. This thesis is an attempt to answer the questions of how and why Nintendo won and Sega lost, and it will do so using four theories as lenses throughout the various gaming literature. These sources are heavily based on interviews with industry insiders, and by comparing and contrasting these sources the hope is to illuminate a new path forward for further research. The examined period has been divided into console generations because this correlates with the console races and eras where companies won or lost. The last section includes two generations in one due to Sega’s quick exit in its last generation. In the early period of the 3rd generation between 1983 and 1987, the focus is on how Nintendo rebuilt the crashed market and Sega struggled to compete against the burgeoning monopoly Nintendo was creating. In the middle period of the 4th generation between 1987 and 1993, Nintendo rose to its most powerful—yet so did Sega, late in the period. With the rivalry intensified, this period showed the climax of the battles taking place in terms of societal consequences and influence. In the last period of the 5th and 6th generations between 1993 and 2001, Nintendo continued going strong while Sega started to struggle against the new contenders entering the market, especially Sony. It is the how and why of these events, looked at through the theoretical framework, that this thesis attempts to highlight in the comparative sections and conclusion

Enhancing automatic level generation for platform videogames

This dissertation addresses the challenge of improving automatic level generation processes for plat-form videogames. As Procedural Content Generation (PCG) techniques evolved from the creation of simple elements to the construction of complete levels and scenarios, the principles behind the generation algorithms became more ambitious and complex, representing features that beforehand were only possible with human design. PCG goes beyond the search for valid geometries that can be used as levels, where multiple challenges are represented in an adequate way. It is also a search for user-centred design content and the creativity sparks of humanly created content. In order to improve the creativity capabilities of such generation algorithms, we conducted part of our research directed to the creation of new techniques using more ambitious design patterns. For this purpose, we have implemented two overall structure generation algorithms and created an addi-tional adaptation algorithm. The later can transform simple branched paths into more compelling game challenges by adding items and other elements in specific places, such as gates and levers for their activation. Such approach is suitable to avoid excessive level linearity and to represent certain design patterns with additional content richness. Moreover, content adaptation was transposed from general design domain to user-centred principles. In this particular case, we analysed success and failure patterns in action videogames and proposed a set of metrics to estimate difficulty, taking into account that each user has a different perception of that concept. This type of information serves the generation algorithms to make them more directed to the creation of personalised experiences. Furthermore, the conducted research also aimed to the integration of different techniques into a common ground. For this purpose, we have developed a general framework to represent content of platform videogames, compatible with several titles within the genre. Our algorithms run over this framework, whereby they are generic and game independent. We defined a modular architecture for the generation process, using this framework to normalise the content that is shared by multiple modules. A level editor tool was also created, which allows human level design and the testing of automatic generation algorithms. An adapted version of the editor was implemented for the semi-automatic creation of levels, in which the designer may simply define the type of content that he/she desires, in the form of quests and missions, and the system creates a corresponding level structure. This materialises our idea of bridging human high-level design patterns with lower level automated generation algorithms. Finally, we integrated the different contributions into a game prototype. This implementation allowed testing the different proposed approaches altogether, reinforcing the validity of the proposed archi-tecture and framework. It also allowed performing a more complete gameplay data retrieval in order to strengthen and validate the proposed metrics regarding difficulty perceptions

Walking Through Doors Is Hard, Even Without Staircases: Proving PSPACE-Hardness via Planar Assemblies of Door Gadgets

A door gadget has two states and three tunnels that can be traversed by an agent (player, robot, etc.): the "open" and "close" tunnel sets the gadget's state to open and closed, respectively, while the "traverse" tunnel can be traversed if and only if the door is in the open state. We prove that it is PSPACE-complete to decide whether an agent can move from one location to another through a planar assembly of such door gadgets, removing the traditional need for crossover gadgets and thereby simplifying past PSPACE-hardness proofs of Lemmings and Nintendo games Super Mario Bros., Legend of Zelda, and Donkey Kong Country. Our result holds in all but one of the possible local planar embedding of the open, close, and traverse tunnels within a door gadget; in the one remaining case, we prove NP-hardness. We also introduce and analyze a simpler type of door gadget, called the self-closing door. This gadget has two states and only two tunnels, similar to the "open" and "traverse" tunnels of doors, except that traversing the traverse tunnel also closes the door. In a variant called the symmetric self-closing door, the "open" tunnel can be traversed if and only if the door is closed. We prove that it is PSPACE-complete to decide whether an agent can move from one location to another through a planar assembly of either type of self-closing door. Then we apply this framework to prove new PSPACE-hardness results for eight different 3D Mario games and Sokobond.Comment: Accepted to FUN2020, 35 pages, 41 figure