[Dev Log] Designing Strategic Chains: Implementing the "Harmonic Sequence" System

In my current deck-building game project, I've implemented a new system called "Harmonic Sequence" (HS) that fundamentally changes the tactical flow of battle.

In this post, I'll focus on the design philosophy behind this system and how it reshapes the gameplay experience.

1. Design Philosophy of "Harmonic Sequence"

The Harmonic Sequence is a special combo action triggered by a specific card (Starter), allowing the player to unleash a series of cards from their hand in a single burst.

The Goal: Shifting from "Static" to "Dynamic"

In card games, the process of gathering the right cards can often feel static. HS is designed to release that built-up potential in a single, explosive moment, achieving three main goals:

• Creating Burst Damage: Breaking the standard card-play limits to push the maximum damage output per turn.
• Giving Meaning to Search Cards: As seen in the demo with "Search Protocol," the act of pinpointing a specific number becomes a direct path to victory.
• A Gateway to "Break": Continuous hits provide an effective way to shred enemy shields, making high-hit counts a pillar of the strategy.

2. Actual Gameplay Flow

The sequence shown in the demo (around 0:14) provides the following player experience:

1. Preparation: Use search cards to assemble a "sequence" in your hand.
2. Ignition: Activate "HS: Starter." At this moment, the game shifts into a high-tempo combo mode.
3. Selection: Select cards in ascending order. The preview area builds anticipation as the chain grows.
4. Release: All cards trigger in rapid succession, shattering shields and dealing devastating damage.

This isn't just about lining up numbers; it’s about creating a system where the player’s long-term planning pays off in a satisfying execution.

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【Column】 Behind the Scenes: Refining UI/UX to Prevent Misclicks and Improve Feel

Note: This section is a technical column focusing on the implementation hurdles and UX improvements.

To support a powerful action like Harmonic Sequence without overwhelming the player, I performed a major overhaul of the UI to balance error prevention with visual clarity.

1. Balancing Error Prevention with Scalability

I changed card activation to a double-click specification. This prevents players from accidentally playing a card when they only intended to click it to check details.
Internally, the logic has been expanded to allow for target selection even as the number of enemies increases. Along with this, I've fine-tuned the behavior of "unplayable cards" (e.g., due to cost) to make it immediately clear what actions are available.

2. Enhancing In-game Guidance

To ensure players never feel lost, I implemented a hint system that triggers on a single click: "Left-click to Use, Right-click to Cancel." This provides an intuitive learning curve for the new control scheme.

3. Visual Feedback and Logical Consistency

I added a glow effect to the attribute panels to strengthen visual feedback. Simultaneously, I updated the internal validation:

• Strict Attribute Validation: Added a flag to each card to determine if it can receive attribute modifiers.
• Eliminating Invalid Combinations: Cards like "Block," where attributes wouldn't strategically make sense, are now flagged to prevent attribute panels from being attached, maintaining logical consistency.

4. Polish and Nomenclature

Based on external feedback, I refined some terminology to better fit the game's context:

• Rename: Changed "Tutorial" to "demo". It’s a small change, but crucial for controlling the player's psychological framing and the overall "vibe" of the experience.

Improving the "feel" of the UI provides the foundation for players to focus entirely on strategy. I’ll continue tuning the interface to ensure every action feels rewarding.