Quick Start

Overview

In this guide, you’ll create a simple fire projectile spell using the spell handler system. The spell will:

Launch a flaming projectile that tracks targets
Ignite enemies on hit
Deal critical damage to already burning enemies
Have 3 charges that regenerate over time

This tutorial is based on the flame_flicker demo spell included in the pack.

Understanding the Spell System

The modular spell system uses a handler-based architecture where you wrap your custom skill logic with the Spell handler. The handler automatically manages:

Cooldowns and charge systems
Warmup/channeling mechanics
Stat calculations (damage, crit chance, etc.)
Player feedback (sounds, messages, action bar displays)

Every spell needs at least two skills: a cast skill that calls the Spell handler, and an execution skill that contains your actual spell logic.

Creating Your First Spell

Create the Cast Skill

The cast skill is what players will trigger (via item, command, or mechanic). It calls the Spell handler with your spell’s configuration.Create a new file in your skills folder called my_fireball-spell.yml:

my_fireball-spell.yml

# Launch a fireball that ignites enemies
my_fireball-cast:
  Skills:
  - skill:Spell{id=my_fireball-exec;
      name=Fireball;
      type=ABILITY,FIRE;
      spellcd=0;
      charges=3;
      chargecd=2;
      charge_delay=1;
      charge_regen=3}

Parameter breakdown:

id - The skill to execute when the spell is cast
name - Display name shown to players
type - Spell categories (used for modifiers and filtering)
spellcd - Base cooldown in seconds (0 = no cooldown)
charges - Number of charges (0 = no charge system)
chargecd - Time to regenerate one charge
charge_delay - Delay before first charge starts regenerating
charge_regen - Number of charges restored per cycle

Create the Execution Skill

The execution skill contains your spell’s actual behavior. It’s called after the Spell handler validates cooldowns and charges.Add this to the same file:

my_fireball-spell.yml

my_fireball-exec:
  Skills:
  - skill:my_fireball-fire{origin=@forward{uel=true;f=1;yo=-0.2}} 
    @forward{yo=-0.2;f=12;uel=true}

This launches the projectile slightly in front of and below the player’s eye level, targeting 12 blocks ahead.

Create the Projectile Skill

Now we’ll create the actual projectile that fires:

my_fireball-spell.yml

my_fireball-fire:
  Skills:
  - skill:setRandomID
  - setvarloc{var=originloc;v=@origin}
  - projectile{fo=true;ti=3;syo=0;sfo=0;hnp=true;se=false;ham=true;
      velocity=64;i=1;g=0;mr=12;hr=0.4;vr=0.4;drawhitbox=false;
      onTick=my_fireball-tick;
      onHit=my_fireball-hit_entity;
      onEnd=my_fireball-end}

Key parameters:

velocity=64 - Fast projectile speed
mr=12 - Max range of 12 blocks
hr=0.4;vr=0.4 - Hit radius (horizontal and vertical)
onTick - Called every tick while projectile travels
onHit - Called when hitting an entity
onEnd - Called when projectile reaches max range or hits block

Add Visual Effects

Create the tick skill that displays particle effects as the projectile travels:

my_fireball-spell.yml

my_fireball-tick:
  Skills:
  - setvarloc{var=targetloc;
      v=@projectileforward{f=1;
        x="<random.float.-0.25to0.25>*<skill.var.size|1>";
        y="<random.float.-0.25to0.25>*<skill.var.size|1>";
        z="<random.float.-0.25to0.25>*<skill.var.size|1>"}}
  - e:pl{fo=true;origin=@VariableLocation{var=originloc};
      p=small_flame;a=1;db=0.3} @VariableLocation{var=targetloc}
  - e:pl{fo=true;
      origin=@VariableLocation{var=originloc;
        x="<random.float.-0.1to0.1>";
        y="<random.float.-0.1to0.1>";
        z="<random.float.-0.1to0.1>"};
      p=dust_color_transition;size=0.8;a=1;
      color1=#f3420c;color2=#ff0000;} 
    @VariableLocation{var=targetloc;
      x="<random.float.-0.1to0.1>";
      y="<random.float.-0.1to0.1>";
      z="<random.float.-0.1to0.1>"}
  - setvarloc{var=originloc;v=@VariableLocation{var=targetloc}}
  - setprojectiledirection @projectileforward{f=14;
      x="<random.float.-0.25to0.25>";
      y="<random.float.-0.25to0.25>";
      z="<random.float.-0.25to0.25>"}

This creates a flickering flame trail with slight randomization for a more natural look.

Add Damage on Hit

Create the hit skill that damages enemies and applies effects:

my_fireball-spell.yml

my_fireball-hit_entity:
  TargetConditions:
  - burning castinstead my_fireball-hit_entity-critical
  Skills:
  - skill:damage-ability{immune=10;
      damageMod=[
        - variableMath{var=damage;equation="x*0.6"}
      ];
      onHit=[
        - ignite{d=60}
      ]}

This deals 60% of base damage and ignites the target for 3 seconds (60 ticks). If the target is already burning, it triggers the critical hit version instead.Now add the critical hit version:

my_fireball-spell.yml

my_fireball-hit_entity-critical:
  Skills:
  - setvar{var=critical;val=true;type=STRING}
  - skill:damage-ability{
      damageMod=[
        - variableMath{var=damage;equation="x*1.5"}
      ];
      onHit=[
        - ignite{d=200}
      ]}

Critical hits deal 150% damage and ignite for 10 seconds (200 ticks).

Add End Effects (Optional)

Add visual and sound effects when the projectile expires:

my_fireball-spell.yml

my_fireball-end:
  Skills:
  - sound{s=entity.generic.extinguish_fire;p=1.5;v=0.5}
  - e:p{p=flame;a=8;speed=0.2;hS=0.2;vS=0.2}

Test Your Spell

Reload MythicMobs:

/mm reload

Test the spell:

/mm test cast my_fireball-cast

You should see:

A fireball projectile launch forward
Flame particle effects trailing behind
Damage and ignite effects on hit
Critical damage on already-burning targets
Charge system with 3 charges that regenerate

Complete Code

# Launch a fireball that ignites enemies
my_fireball-cast:
  Skills:
  - skill:Spell{id=my_fireball-exec;
      name=Fireball;
      type=ABILITY,FIRE;
      spellcd=0;
      charges=3;
      chargecd=2;
      charge_delay=1;
      charge_regen=3}
      
my_fireball-exec:
  Skills:
  - skill:my_fireball-fire{origin=@forward{uel=true;f=1;yo=-0.2}} 
    @forward{yo=-0.2;f=12;uel=true}

my_fireball-fire:
  Skills:
  - skill:setRandomID
  - setvarloc{var=originloc;v=@origin}
  - projectile{fo=true;ti=3;syo=0;sfo=0;hnp=true;se=false;ham=true;
      velocity=64;i=1;g=0;mr=12;hr=0.4;vr=0.4;drawhitbox=false;
      onTick=my_fireball-tick;
      onHit=my_fireball-hit_entity;
      onEnd=my_fireball-end}

my_fireball-tick:
  Skills:
  - setvarloc{var=targetloc;
      v=@projectileforward{f=1;
        x="<random.float.-0.25to0.25>*<skill.var.size|1>";
        y="<random.float.-0.25to0.25>*<skill.var.size|1>";
        z="<random.float.-0.25to0.25>*<skill.var.size|1>"}}
  - e:pl{fo=true;origin=@VariableLocation{var=originloc};
      p=small_flame;a=1;db=0.3} @VariableLocation{var=targetloc}
  - e:pl{fo=true;
      origin=@VariableLocation{var=originloc;
        x="<random.float.-0.1to0.1>";
        y="<random.float.-0.1to0.1>";
        z="<random.float.-0.1to0.1>"};
      p=dust_color_transition;size=0.8;a=1;
      color1=#f3420c;color2=#ff0000;} 
    @VariableLocation{var=targetloc;
      x="<random.float.-0.1to0.1>";
      y="<random.float.-0.1to0.1>";
      z="<random.float.-0.1to0.1>"}
  - setvarloc{var=originloc;v=@VariableLocation{var=targetloc}}
  - setprojectiledirection @projectileforward{f=14;
      x="<random.float.-0.25to0.25>";
      y="<random.float.-0.25to0.25>";
      z="<random.float.-0.25to0.25>"}

my_fireball-hit_entity:
  TargetConditions:
  - burning castinstead my_fireball-hit_entity-critical
  Skills:
  - skill:damage-ability{immune=10;
      damageMod=[
        - variableMath{var=damage;equation="x*0.6"}
      ];
      onHit=[
        - ignite{d=60}
      ]}

my_fireball-hit_entity-critical:
  Skills:
  - setvar{var=critical;val=true;type=STRING}
  - skill:damage-ability{
      damageMod=[
        - variableMath{var=damage;equation="x*1.5"}
      ];
      onHit=[
        - ignite{d=200}
      ]}

my_fireball-end:
  Skills:
  - sound{s=entity.generic.extinguish_fire;p=1.5;v=0.5}
  - e:p{p=flame;a=8;speed=0.2;hS=0.2;vS=0.2}

Understanding Spell Parameters

The Spell handler accepts many configuration parameters. Here are the most commonly used:

Basic Parameters

Parameter	Type	Default	Description
`id`	string	required	The skill to execute when cast
`name`	string	required	Display name for the spell
`type`	string	”ABILITY”	Spell category/tags (comma-separated)
`spellcd`	float	1	Base cooldown in seconds
`damage`	float	caster.damage	Base damage value

Charge System

Parameter	Type	Default	Description
`charges`	int	0	Max charges (0 disables charge system)
`chargecd`	float	3	Seconds to regenerate one charge
`charge_regen`	int	1	Charges restored per cycle
`charge_delay`	float	0	Delay before first charge regens

Warmup/Channeling

Parameter	Type	Default	Description
`warmup`	float	0	Channel time in seconds before cast
`onChannelStart`	skill	channel-start_fx	Skill called when channeling starts
`onChannelTick`	skill	channel-tick_fx	Skill called each tick while channeling
`onInterrupt`	skill	[]	Skill called when channel is interrupted

Advanced Stats

Parameter	Type	Default	Description
`critical_chance`	float	0.01	Chance to crit (0-1)
`critical_damage`	float	0	Bonus crit damage multiplier
`velocity`	float	48	Projectile velocity
`range`	float	32	Max spell range

Next Steps

Now that you’ve created your first spell, you can:

Explore the demo spells in skills/Demo Skills/Demo Spells/ for more examples
Learn about the damage system and modifiers
Create custom visual effects with particles
Build spell combos and interactions
Implement mana costs and resource management

Check out the burning_blast-spell.yml demo for an advanced example featuring warmup channeling, dynamic retargeting, and explosive area damage.

Get Started

Core Concepts

Input Handlers

Skill Handlers

Skill Mechanics

Examples

Overview

Understanding the Spell System

Creating Your First Spell

Complete Code

Understanding Spell Parameters

Basic Parameters

Charge System

Warmup/Channeling

Advanced Stats

Next Steps

Build docs developers (and LLMs) love

Get Started

Core Concepts

Input Handlers

Skill Handlers

Skill Mechanics

Examples

​Overview

​Understanding the Spell System

​Creating Your First Spell

​Complete Code

​Understanding Spell Parameters

​Basic Parameters

​Charge System

​Warmup/Channeling

​Advanced Stats

​Next Steps

Build docs developers (and LLMs) love

Overview

Understanding the Spell System

Creating Your First Spell

Complete Code

Understanding Spell Parameters

Basic Parameters

Charge System

Warmup/Channeling

Advanced Stats

Next Steps