Limits

The plugin has two things called a limit and they are not the same thing. One counts bots. The other bounds a number inside one bot. Confusing them is how a server ends up with a cap it did not mean to set.

max-bots — how many bots exist

One number, at the bottom of config.yml, for the whole server.

# How many bots may exist on the server at once.
# Every bot thinks once per tick and searches for its own path,
# so this is a real ceiling and not a formality. Raise it only
# after watching the tick time with the current one full.
max-bots: 16

The comment is not boilerplate. A bot is not a decoration that sits in a chunk: it observes, decides, aims, moves and swings every single tick, and when terrain gets in its way it runs its own bounded grid search on top of that. Sixteen bots is sixteen of those per tick. The number that tells you whether you can raise it is your tick time with the current ceiling full, not the number itself.

Every spawn goes through one place, so the ceiling has one place to live: /bot spawn, the menu's spawn button, an automatic respawn and a bot another plugin asks for are all counted the same way. At the ceiling the spawn fails with BotLimitReachedException, and the player reads bot.limit-reached:

bot:
  limit-reached: "%prefix% {error}The server is already running %limit% bots. Try again in a moment."

%limit% is the ceiling that refused the spawn.

max-bots is read as at least 1: setting it to zero or a negative number does not disable the plugin, it leaves you with a ceiling of one.

The limits block — how far a slider goes

Every numeric setting in the advanced menu is a pair of buttons that adds or subtracts a step. This block is where each of those stops.

# Bounds the in-game menu clamps its sliders to.
limits:
  min-attack-speed: 0.25
  max-attack-speed: 4.0
  min-movement-speed: 0.25
  max-movement-speed: 3.0
  min-attack-reach: 1.0
  max-attack-reach: 6.0
  min-follow-distance: 1.0
  max-follow-distance: 12.0
  min-attack-damage: 0.5
  max-attack-damage: 40.0
  min-max-health: 1.0
  max-max-health: 40.0
  min-shield-disable: 0.0
  max-shield-disable: 20.0
  # Totems stop at -1, which is the unlimited setting.
  min-totems: -1.0
  max-totems: 16.0

Two things about how a slider lands on its value:

• It rounds to one decimal. A step is applied, clamped into the range, and then rounded, so a slider never accumulates a trailing fraction no matter how many times it is nudged.
• Totems bottom out at -1, and -1 means unlimited. It is not a floor of "none" — 0 is none, the totem in the kit and nothing after it. One step below that is a bot that never runs out, which the menu shows as ∞.

Raising a maximum is a design decision about your server, not a performance one: a bot with forty half-hearts and six blocks of reach costs the same tick time as a default one. max-bots is the key that costs tick time. See Behaviour for what a bot actually does with its tick, and Configuration for every key in the file.