Coding the Core Loop: Simple Logic Behind Popular Auto-Battler Mechanics for Beginners

Auto-battlers, also known as auto chess games, have exploded in popularity. Titles like Teamfight Tactics, Dota Auto Chess, and Super Auto Pets capture players with their unique blend of strategy, randomness, and passive combat. But how do these games actually work under the hood? For aspiring game developers, understanding and coding auto-battler mechanics might seem daunting. The secret often lies in understanding the game’s core loop – the fundamental cycle of actions the player repeats. This guide will break down the simple logic behind popular auto-battler mechanics, focusing on the core loop for beginners.

Before diving into auto-battlers specifically, let’s clarify what a “core loop” is in game design. It’s the sequence of primary activities a player performs over and over again. Think of classic games: in Pac-Man, it’s Eat Dots -> Avoid Ghosts -> Eat Power Pellet -> Chase Ghosts -> Repeat. A well-designed core loop is engaging, satisfying, and keeps players coming back. Designing this loop effectively is crucial for player retention and creating that addictive “one more round” feeling.

Deconstructing the Auto-Battler Core Loop

Most auto-battlers share a similar core gameplay loop, typically broken down into distinct phases. Understanding these phases is the first step towards coding auto-battler mechanics.

• Preparation/Shop Phase: This is where the player makes most of their strategic decisions.
• Combat Phase: Units automatically fight based on their stats, abilities, and positioning.
• Resolution/Reward Phase: The outcome of the combat is determined, and players receive rewards.

Let’s look at the logic involved in each.

The Preparation/Shop Phase Logic

This phase involves several key mechanics:

• Unit Shop: Players are presented with a random selection of units to purchase.
  • Simple Logic: Maintain a pool of available units, possibly tiered by rarity. Each “reroll,” draw a specified number of units randomly from the pool based on the player’s level (higher levels might grant access to rarer units or more shop slots). Ensure purchased units are removed from the immediate selection.
• Gold Management: Players earn gold each round and potentially bonus gold for streaks or interest. They spend gold on units, rerolls, or leveling up.
  • Simple Logic: Track player gold in a variable. Add base income + streak/interest bonuses after combat. Subtract costs when units are bought, the shop is rerolled, or the player levels up. Interest often calculates as 1 gold per 10 gold saved, capped at a certain amount.
• Unit Placement & Upgrades: Players place units on a board and often combine duplicates (usually three) to create stronger, upgraded versions.
  • Simple Logic: Use a grid system for the board. Check if placing a unit exceeds the team limit (often tied to player level). For upgrades, check if the player owns three identical units (same character, same star level). If so, remove the three and replace them with one higher-star unit.

[Hint: Insert image/video showing a typical auto-battler shop interface and board placement here]

The Logic Behind Auto-Combat

Once the preparation timer runs out, combat begins automatically. This is where the “auto” part comes in, but there’s still underlying logic dictating the action.

• Targeting: Units need to decide who to attack.
  • Simple Logic (Melee): Find the closest enemy unit within attack range.
  • Simple Logic (Ranged): Find the closest enemy unit within a larger attack range. Variations include targeting the lowest health enemy, the highest threat enemy, or a random enemy.
• Attacking: Units attack their chosen target periodically.
  • Simple Logic: Each unit has an attack speed (e.g., attacks per second). Use a timer. When the timer reaches zero, perform an attack, calculate damage, and reset the timer based on attack speed.
• Damage Calculation: How much hurt does an attack inflict?
  • Simple Logic: Basic Attack Damage – Target’s Armor/Defense = Damage Dealt. Ensure damage isn’t negative. Apply this damage to the target’s current Health Points (HP).
• Unit Abilities (Optional but Common): Many units have special skills triggered by conditions like taking/dealing damage or after a timer.
  • Simple Logic: Track a “mana” bar for each unit. Increase mana when attacking or taking damage. When mana is full, trigger the ability (e.g., deal area damage, heal an ally, stun an enemy), reset mana, and apply effects.
• Defeat Condition: When a unit’s HP reaches zero, it’s removed from combat.

This phase continues until only one player (or neither, in a draw) has units remaining on the board.

Wrapping Up: Resolution and Rewards

After combat:

• Determine Winner/Loser: Check which player still has units.
• Player Damage (Loser): The losing player takes damage based on the number and tier of surviving enemy units.
  • Simple Logic: Assign damage values to each surviving unit tier + potentially a base damage amount. Sum this up and subtract it from the losing player’s health.
• Award Gold/XP: Grant base gold, potential win/loss streak gold, and interest gold to both players. Award experience points (XP) used for leveling up.

This completes one cycle, and the core loop repeats, starting again with the Preparation/Shop phase.

Coding Auto-Battler Mechanics: Simple Examples

You don’t need complex AI for a basic auto-battler. Here’s how you might represent the core ideas in pseudo-code or simple descriptions:

• Unit Data Structure:

  Unit {
    Name: String
    HP: Integer
    MaxHP: Integer
    AttackDamage: Integer
    AttackSpeed: Float (attacks per second)
    AttackRange: Float
    Position: Vector2 (x, y)
    Target: Unit (reference to target)
    AttackTimer: Float
  }
      

• Basic Targeting Logic (inside Unit update):

  if (Target is null or Target.HP <= 0 or distance(Position, Target.Position) > AttackRange):
    FindClosestEnemyUnitWithinRange() -> assign to Target
      

• Basic Attack Logic (inside Unit update):

  if (Target is not null):
    AttackTimer -= DeltaTime // Time since last frame
    if (AttackTimer <= 0):
      Damage = AttackDamage // Add defense calculation later
      Target.TakeDamage(Damage)
      AttackTimer = 1.0 / AttackSpeed // Reset timer
      

Focusing on these simple representations is key when first learning about coding auto-battler mechanics.

Getting Started with Coding Auto-Battler Mechanics

Ready to try building your own? Here are some tips:

• Choose an Engine: Game engines like Unity (using C#) or Godot (using GDScript or C#) are excellent choices with plenty of resources for beginners.
• Start Simple: Don't try to clone TFT on day one. Focus on the absolute core: buying 1-2 types of units, placing them, and having them perform basic auto-attacks based on proximity.
• Iterate: Get the basic loop working, then gradually add features: gold, upgrades, different unit types, simple abilities, synergies.
• Learn from Others: Look at tutorials or open-source examples. Many developers share their progress online. Check out resources like our guide to basic game loops for foundational concepts.

[Hint: Insert video demonstrating a very simple auto-battler prototype being built or played]

Conclusion

The core loop of an auto-battler, while potentially leading to complex strategic depth, is built upon relatively simple, repeatable logic. By breaking down the Preparation, Combat, and Resolution phases, beginners can grasp the fundamentals needed for coding auto-battler mechanics. Start with basic implementations of the shop, unit stats, targeting, and attacking, then iterate by adding layers of complexity like upgrades, abilities, and synergies. Understanding this core loop is the first major step towards creating your own engaging auto-battler game.