Shamano | RLIZA’s blog

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📝 Design Background

This unfinished prototype was proposed in a game jam organized by Tencent. UNO, a board card game inspired our idea of making a card battle game in a tribal background, which includes some special Shaman Spells. Why did we connect UNO and battle? This is relevant to the rules of UNO, which encourage players to play all their cards as soon as possible. But the problem is, sometimes you have too many cards that you cannot win others with fewer cards, or to say, the UNO game is largely affected by your luck—drawing and dealing the right color and powerful cards—sometimes you find yourself powerless to change the game. So we added some new rules to allow players to attack others when they play specific cards, so they could also control the game even if they have many cards! So, now the rule is, defeating other players or playing all your cards!

In this game production, I designed some rules of the game, designed and coded the logic of AI, fixed many bugs, and produced many special visual effects. Besides, we've utilized AI-generated artwork to create the backgrounds and character illustrations, which may result in a lack of refined design and aesthetic appeal. We appreciate your understanding as we continue to improve these aspects.

🤗 Basic Rules

Card Color

Considering the basic card colors of the classic UNO, we find it very appropriate to give each card color a special role. For example, the basic card colors include red, yellow, green, and blue, and in UNO, they have no special function but just as a designated color to restrict cards that can be played, so different colors do not interact, leading to the lack of fun and closure. So we allocate some features to different colors. Red number cards can cause double damage to the card face number, blue ones can heal the health value of the number, green ones can generate a corresponding shield value, and yellow ones can let the target draw a card. So now different colors correspond to distinct strategic actions: red signifies aggression and attack, green represents defense, yellow corresponds to control or disrupting an opponent's card-playing rhythm, and blue is associated with healing and self-preservation. To differentiate the functions of green and yellow, we have imposed a limitation on shields, which now last for only one turn (from the end of one action to the start of the next). Furthermore, if the attack points of a yellow card are less than the shield value, it will not trigger the forced card draw effect on the opponent.

Card Type

Apart from the basic number cards, we designed functional cards and skill cards. The former includes Wild Draw, Wild Draw4, Draw2, Reverse, and Skip; while the latter possesses some special effects and skills. Besides, Wild Draw can also spell specific skills of the character.

Functional Card

Wild Draw can change the current color, Wild Draw4 can change the color and let the next player draw 4 cards, if this player has a Draw4 card, he or she can also utilize this card to stack a +4 effect onto the next player without incurring any impact on themselves. The Draw2 can make the next player draw 2 cards, while he or she still can use a +4 card or +2 card to stack the corresponding effect onto the next player. Red Reverse can switch the direction of card play between clockwise and counterclockwise. The last, Skip causes the next player to miss their turn, effectively passing the action directly to the player after them.

Skill Card

Every skill card has a specific effect. Some cards can reflect draw effects back onto the player who played them, or even exchange health points with a designated opponent, among other abilities. The specific effects of these skills depend on the color of the skill card and the character wielding it; different characters may exhibit varied effects when using skill cards of the same color.

AI Logics

Having learned about the basic card type, we need to address the behavioral strategies that the AI should follow. How should the AI select the current color and the target for attack? When there are multiple colors available, which one should take precedence? To answer these questions, we must first review the gameplay experience we aim to achieve: to minimize the impact of luck in matches and enhance the influence of the player's strategic actions on the game's outcome, thus increasing the player's sense of control over the game. Therefore, I have designed the AI to act according to the following priorities: Control > Attack > Shield > Healing. In this way, AIs will control your card-playing rhythm and attack you when you have fewer cards and blood points, so other players can also meticulously plan their card-play sequence to make a stunning comeback even in the most desperate situations.

Based on the health, shield values, and remaining number of cards of all players on the field, it assigns different weights to calculate the corresponding probability of being targeted, as the following equation:

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In this way, we have a simple AI behavioral pattern, after fixing many bugs about behavior trees and the code frame, we can now run the game and assess its playability based on match outcomes. We can then fine-tune the numbers and rules accordingly!

Existing Problems and Feedback

Now we find some problems: the player who is targeted first has a higher probability of being hit, which implies that they are often at a disadvantage in subsequent actions. This is because the calculation of the hit probability factors in the player's health level, with lower health resulting in a higher chance of being hit. To address this issue, we have several adjustment strategies: one is to reduce the health factor or increase the maximum health, thereby diluting the impact of health on the hit probability; another is to introduce a new mechanism or system that increases a certain resource (such as an anger gauge) after being hit, giving them more options in subsequent actions. The specific decision will need to be determined through further testing.

Prospective Iteration Direction

We are considering the introduction of multiplayer mode in the future to conduct more comprehensive testing and gather valuable feedback from players.

We will add new skills and descriptions in the future.

Enhance the readability of skills by incorporating additional UI elements, special effects, and auxiliary visual cues.

Implement a user-friendly onboarding process to ensure that players unfamiliar with UNO-style games can easily get started and enjoy the experience!