How much rng?

During my ongoing literature review I often discover interesting facts about things I’ve never thought about. Sometimes I can connect these facts with my own observations: The result is mostly a completely new idea why things are as they are. Maybe these ideas are new to you, too. Therefore I’ll share my new science based knowledge with you!

This week: Turn-based strategy games can be quite challenging by using methods to create a certain randomness. Players have to adapt their strategies and don’t experience the same on a second playthrough.

Recently, I began with a new playthrough of XCOM – Enemy unknown[1] on the highest difficulty level (appropriately called „Impossible“ [2] difficulty) with „ironman“ [2] mode enabled. The ironman mode increases the difficulty by disabling the option to reload older savegames and the progress is automatically saved. By using this option all the player’s decisions are final for that particular playthrough. However, XCOM is a turn-based strategy game and thus requiring a thoughtful gameplay. Therefore, the ironman mode is mostly increasing the need for well considered decisions.

Headquarter

On impossible difficulty, the first phase of the game is the most important one. Doing something wrong during this period makes it harder to win the game or can even screw the whole playthrough. Considering this, the player is challenged to develop a strategy to survive the beginning of the game.
The game has four different aspects: Turn-based fights, research and development, base building and strategic planning. All these four aspects influence each other and need to be mastered to successfully play the game.

However, during the first month of the game, the player is short on funds and there’re only three ways of increasing the player’s funds: Completing missions, receiving new funds at the end of a month or selling rare resources (the worst way of making money). The amount of fundings is increased by protecting the nations of the XCOM Project [3].
If the player wants to protect a nation, they need to build a satellite and place it above the particular nation. This is an expensive process, especially during the first month. Additionally, at the end of the first month, the player is in danger of loosing four nations, if they haven’t build four satellites. This leaves the player with only one option: building four satellites until the end of the first month is the only strategy to survive the first month without losing any nation.

Nations of XCOM

This strategy requires the right choices and the luck to receive the first three missions of the game within the first 15 days of the game [4]. If the player is unlucky and only receives two missions, they might have a second chance and gather enough resources to sell during these two missions. However, this isn’t granted at all.
In conclusion, the player has only one strategic option to keep every nation in the XCOM Project. The game on the other hand is very random. As mentioned before, the player can be unlucky and doesn’t receive all the resources needed for the ideal strategy.

The fortune of the player is determined by the random-number-generator (rng) [5] of the game. Among other things, the rng determines the dates of the missions and the resources gathered by completing a mission. Rng can be implemented through an pseudo-random number generator algorithm that can create a sequence of numbers without almost no pattern [6].

Adding randomness to a game can help a virtual world seem more real [7]. The Player isn’t experiencing the same during a new playthrough and there’s no right strategy to play the game successfully [5]. Additionally, the gameplay of strategy games can benefit from unpredictable events: the player has to adapt their strategy.
However, the rng only works well, if there’re enough ways to win the game by changing the strategy. As mentioned before, XCOM has only one ideal strategy but uses the rng.

Naturally, the game isn’t lost, if the player loses some nations after the first month, but it gets even harder for the player to survive. There’s no way of adapting the strategy because the development of the player’s base is determined by the available fundings. Additionally, the difficulty of the game increases every month by sending new and stronger aliens against the player.

To wrap things up, rng keeps the game fresh [5], if there’re enough ways to succesfully play the game. However, if the game uses rng but only has one ideal strategy, the player might lose the game without any chance to prevent their doom.

[5] Brathwaite, Brenda; Schreiber, Ian (2009): Challenges for Game Designers, Boston.

[7] Perry, David; DeMaria, Rusel (2009): David Perry on Game Design: A Brainstorming Toolbox, Boston.