Seasonal Skills With Mythic Mobs

Make MythicMobs skills react to the season and to a player's body temperature, and run them from a season file. The guide has five steps.

What you need

  • MythicMobs. MythicSeasons copies its skill pack at server start, so restart once if you added MythicMobs after MythicSeasons first started.
  • The mythicseasons.admin permission (operators have it).
  • A test world in the shipped winter season: run /ms set winter in it.
  • The shipped temperature.yml with enabled: true. The playertemp condition never matches while it is false.

Paths are relative to plugins/MythicSeasons unless they start with plugins/.

How the pieces fit

MythicSeasons casts every skill in a season's player-tick list for each player in a world in that season, every performance.skill-trigger-interval ticks (5 by default, four times a second), with the player as the caster.

Step 1: Look at the bundled pack

MythicSeasons copies its pack to plugins/MythicMobs/packs/MythicSeasons/:

plugins/MythicMobs/packs/MythicSeasons
  packinfo.yml
  skills
    Ambient.yml
    Atmosphere.yml
    AtmosphereSeasons.yml
    BlockHeat.yml
    Temperature.yml
    TemperatureModifiers.yml
    TemperatureReadout.yml

Its skills start with MS_. MS_ColdHunger in Temperature.yml is a typical one:

MS_ColdHunger:
  Cooldown: 3
  Conditions:
  - playertemp{max=5}
  Skills:
  - potion{type=HUNGER;duration=80;lvl=0} @Self

Packs lists every skill of the pack.

Step 2: Write your own skills

Create plugins/MythicMobs/Skills/SeasonalSkills.yml with two skills:

Winter_Bite:
  Cooldown: 60
  Conditions:
  - season{season=winter}
  - playertemp{max=5}
  Skills:
  - message{m="<aqua>The winter cold bites at you. Find a fire."} @Self

Winter_Layers:
  Conditions:
  - season{season=winter}
  Skills:
  - modifytemp{id=layers;amount=4;duration=2} @Self
  • Cooldown: 60 is in seconds. Without it Winter_Bite would run four times a second.
  • season is true while the caster's world is in one of the listed seasons, such as season{season=fall,winter}.
  • playertemp compares the body temperature in degrees Celsius. max=5 means 5 or lower, and min= sets a lower limit.
  • modifytemp adds amount degrees to the body temperature under the name id, for duration seconds after the last cast. A new cast with the same id replaces the earlier value instead of adding to it.

Step 3: Add the skills to the season

Add the two names at the end of the player-tick list in seasons/winter.yml, and keep every other line:

skill-triggers:
  player-tick:
    - MS_Atmosphere
    - MS_ColdHunger
    - MS_ColdSlowness
    - MS_ColdFreezing
    - MS_HeatNoHealing
    - MS_HeatSlowness
    - MS_HeatFire
    - MS_BlockHeat
    - MS_TemperatureRecovery
    - MS_TemperatureModifiers
    - MS_TemperatureReadout
    - MS_TemperatureWarnings
    - Winter_Bite
    - Winter_Layers
  player-tick-particles:
    - MS_ColdBreath
    - MS_NightSparks
  world-tick: []
  season-start: []
  season-end: []

Skill names are case sensitive.

Step 4: Reload both plugins

Run the MythicMobs reload first, then the MythicSeasons reload:

/mm reload
/ms reload
You changed Run
A skill file in plugins/MythicMobs/Skills or a file of the bundled pack /mm reload
A season or event file, calendar.yml, crops.yml, temperature.yml or config.yml (except the keys in the next row) /ms reload
A biome file, griefprevention.yml, or these keys in config.yml: the three performance timers (chunk-supplier-interval, skill-trigger-interval, autosave-interval-minutes), biome-display-name and optimized-custom-biomes Restart the server

Chat shows Reloaded and Biome file changes need a restart. A few seconds later the console should show no Skill trigger references unknown MythicMobs skill line.

Step 5: Test

  1. Stand in the winter test world in survival mode. Take off your armour, hold nothing, stay out of water and rain, keep away from lava, fire, campfires, torches and lanterns, and do not sprint.
  2. Read the temperature on the action bar, shown as [ <number>°C ]. At 5 or below it also shows Heat up! in front of the number.
  3. Wait about thirty seconds. The number rises by about 4 degrees, the modifier that Winter_Layers keeps alive.
  4. While your body temperature is 5 or lower, chat shows The winter cold bites at you. Find a fire. once a minute. Test at night: around midday the reading, which includes the 4 degrees of Winter_Layers and 5 more while the hunger bar holds 18 points or more, can stay above 5. The pack's own warning, Warning! Your temperature is really low, heat up quickly!, can show too.

When you are done testing, remove the two names from winter.yml and run /ms reload, unless you want the skills in your winter.

If nothing happens

Symptom Cause
The console says Skill trigger references unknown MythicMobs skill: Winter_Bite MythicMobs does not know that name. Check spelling and case, and run /mm reload. The line is logged once per name
The console says Failed to cast skill 'Winter_Bite': followed by a message An error while casting. Read the message and fix the skill
/ms getinfo prints Seasons are off in this world The world has no season. Run /ms set winter
The number on the action bar never changes Temperature is off in the world (/ms temperature toggle turns it on again), or a WorldGuard region or a claim fixes the temperature
There is no number on the action bar MS_TemperatureReadout is not in the season's player-tick, enabled is false in temperature.yml, the player is in creative or spectator mode or turned temperature off with /toggletemperature, or another plugin keeps writing to the action bar
The message never shows The body temperature stays above 5, or the 60 second Cooldown is still running

See Skills Not Firing for the full checklist.

Next steps

Updated Nov 11, 2026