START → PLAYER_TURN → ENEMY_TURN → PLAYER_DODGE → CHECK_VICTORY → END ↑_______________↓ (repeat)
function EncounterStarting() -- Code that runs once when the battle starts -- Set initial variables, maybe play a custom animation end
Ask yourself:
Scripts can change the properties of the player's soul. For example, Papyrus’s script introduces , where gravity affects the player. Undyne’s script introduces Green Soul Mode , where the player stands still and must block spears with a shield. To implement this, your script would use a function like SetSoulMode("blue") when the wave starts. Undertale Boss Battles Script
function OnHit(bullet) -- Script for when a bullet hits the player if bullet.is_blue then Player.Hurt(bullet.damage * 2) -- Blue attacks hurt moving players end end
Undertale's boss battles are not just challenges to overcome; they are narratives to experience. The script for each fight is expertly written to make you feel every emotion, from love and friendship to despair and rage, making it one of the most impactful, "script-driven" games of all time.
// Condition 3: Specific item used? if (global.last_used_item == "umbrella") can_spare = true; START → PLAYER_TURN → ENEMY_TURN → PLAYER_DODGE →
The most searched variation of this keyword is the . Sans breaks the rules. He attacks first, dodges your attacks, and uses gravity and platforming. Here is a snippet of a high-level Sans script.
is a fan‑made engine that recreates Undertale’s battle system inside the Unity engine, but restricts itself to battles only—no overworld. Create Your Frisk (CYF) is a constantly updated fork of Unitale, offering bug‑fixes, performance improvements, and new features. The original Unitale is now outdated (over three years old), so CYF is the strongly recommended choice for new projects. Both engines use Lua for scripting, and battles are built by editing .lua files placed inside a mods folder.
Not every script is about fighting. In the Alucare guides for secret bosses like So Sorry and Glyde, the scripts involve extremely specific conditions to even start the battle (such as inputting a specific name or waiting for a specific real-world minute). Scripting these events requires modifying the Global.Plot variable, which tracks the player's progress in the story. To implement this, your script would use a
Retribution, despair, and breaking the fourth wall.
If you prefer a different ecosystem, several modern alternatives exist:
# Define Flowey's stats flowey_stats = 'hp': 30, 'attack': 3, 'defense': 2