Put your own sound effects here to replace the built-in ones (free CC0 sounds by Kenney.nl).
Name the file after the sound key: <key>.ogg  or  <key>.mp3  or  <key>.wav
Add <key>_2.ogg, <key>_3.ogg ... (up to _9) for random variants.
If a key has any file here, only your files are used for it; delete them to get the built-in sound back.
Keep sounds short (under ~2 seconds). Restart the game after adding files.

Keys:
  hit.ogg            - normal hit on a monster (Boss pick: 'Axe Slash 1' by smokebomb99, CC0)
  hit_crit.ogg       - critical hit (Boss pick: 'Hit Impact Sword 3' by CogFireStudios, CC0)
  super_ting.ogg     - super-crit extra layer: clear small-bell 'ting' (synth, tools/sfx_synth/super_ting.py)
  miss.ogg           - attack missed (whoosh)
  hit_player.ogg     - you take damage (classic short tight thump, bright)
  hit_player_layer.ogg - hit-taken layer: crisp tap
  monster_die.ogg    - monster dies
  monster_die_boss.ogg - boss / MVP dies
  level_up.ogg       - base level up
  job_level_up.ogg   - job level up
  skill_cast_start.ogg - casting begins (magic circle)
  skill_fire.ogg     - Fire Bolt / Fire Ball / Blazing Burst / Fire Wall
  skill_cold.ogg     - Ice Bolt / Freezing Lance
  skill_lightning.ogg - Lightning Bolt / Thunderstorm
  skill_holy.ogg     - holy damage, buffs (Blessing, Swiftness...)
  skill_heal.ogg     - Heal
  skill_charge.ogg   - skill wind-up: magic gathering (synth, CC0)
  skill_whoosh.ogg   - skill release: swing / throw whoosh (synth, CC0)
  skill_boom.ogg     - big skill impact: Bash, Blazing Burst, Fire Ball (synth, CC0)
  skill_coins.ogg    - Coin Strike coins (synth, CC0)
  skill_poof.ogg     - Burrow smoke puff (synth, CC0)
  skill_warp.ogg     - Teleport light pillar (synth, CC0)
  skill_bash.ogg     - physical skills (Bash, Coin Strike, Envenom...)
  arrow_shot.ogg     - bow fires an arrow
  arrow_hit.ogg      - arrow lands
  pickup_item.ogg    - picked up an item
  pickup_zeny.ogg    - got zeny (selling, quest reward)
  equip.ogg          - equipped an item
  refine_success.ogg - refine succeeded
  refine_fail.ogg    - refine failed (item destroyed)
  card_insert.ogg    - card inserted
  portal_warp.ogg    - warp portal / map change
  ui_click.ogg       - button click
  ui_hover.ogg       - mouse over a button (UI v3; bundled: a soft, high ui_click)
  ui_open.ogg        - window opens
  ui_close.ogg       - window closes
  quest_complete.ogg - quest turned in
  footstep.ogg       - footsteps (quiet)
  death.ogg          - you died

In game: N = mute / unmute sound effects (music: M).