Buffs, Moodlets & Moods

1. What a buff actually is

A buff is an active state attached to a Sim. It may be visible or completely hidden, emotional or non-emotional, short-lived or maintained by another system for as long as that system needs it.

2. Important buff fields

The exact XML varies by class and patch, but these concepts are worth recognizing immediately.

Loot on add and remove

Buffs can be used as event points in a state machine.

Buff added
  → loot_on_addition runs
Buff expires / removed
  → loot_on_removal runs

This pattern is especially useful for delayed consequences and cooldowns.

Duration

A temporary buff can function as a timer even when the player never sees it.

Hidden cooldown buff
  → exists for N Sim minutes
  → tests detect that cooldown is active
  → on removal, next state may be triggered

3. Buffs can contain tests too

Buffs are not only passive containers. Depending on the class/tunables involved, buff behavior can be conditional.

Tests can decide whether a modifier, reaction or linked behavior should apply in the current context.

Examples of useful questions include:

• Does the Sim have another trait?
• Is a statistic above or below a threshold?
• Is the Sim currently in a valid age or state?
• Is a target/object/context available?
• Should this branch apply only under specific gameplay conditions?

Conceptually:

Buff active
  → test passes
  → modifier/effect branch applies

This matters because you may see a buff correctly added but still not see the expected effect. The missing piece can be a failing test inside the buff’s behavior rather than the code that added the buff.

4. Buff modifiers are much more than statistics

A common beginner assumption is that buffs mostly modify skills, motives or statistics. They can do considerably more.

Statistic and gameplay modifiers

Buffs can affect:

• skills;
• motives and commodities;
• autonomy scoring;
• relationship or other gameplay values;
• affordance availability;
• walkstyles or locomotion-related behavior;
• other feature-specific game effects.

Appearance modifiers

Buffs can also carry appearance modifiers. These are used when a temporary gameplay state should visibly change the Sim without permanently editing their normal CAS setup.

Typical uses include feature-specific visual overlays, temporary body/face changes, occult or condition effects, and other states that should appear while a buff exists and disappear when it no longer applies.

This is especially useful because the visual state remains coupled to the gameplay state: remove the buff and the temporary appearance effect can disappear with it.

5. Shadow buffs

Some buff systems use shadow buffs: secondary buffs that mirror or represent another state without being the primary player-facing effect.

The exact implementation varies by feature, but the design purpose is usually one of these:

• keep a hidden logical marker separate from the visible moodlet;
• let tests detect a state without depending on a specific visible presentation;
• preserve gameplay state while another buff handles text/icon/mood presentation;
• provide an alternate/internal representation used by another subsystem;
• separate lifecycle/logic from UI-facing behavior.

Conceptually:

Primary buff / visible moodlet
  → shadow buff carries hidden logical state
Other tests/systems
  → check shadow buff instead of relying on UI presentation

Why is that useful? Because the visible buff may be replaced, suppressed, merged with another mood presentation or otherwise changed while the underlying gameplay state still needs to be detectable.

6. Moodlets, moods and emotional scoring

A moodlet is the player-facing presentation of a visible buff. The tuning resource underneath is still a Buff.

A mood is the Sim’s overall emotional state. Emotional buffs contribute weights, and competing influences are evaluated to determine the dominant mood.

Common moods include Fine, Happy, Confident, Flirty, Playful, Focused, Energized, Inspired, Angry, Sad, Uncomfortable, Tense, Embarrassed, Bored, Dazed and later-added emotions such as Scared.

7. Common buff design patterns

Visible emotional moodlet

Interaction succeeds
  → loot adds visible buff
  → buff contributes mood weight
  → player sees moodlet

Hidden cooldown

Action occurs
  → hidden buff added for 8 Sim hours
  → test blocks repeated action while buff exists
  → cooldown buff expires

Temporary appearance state

Gameplay event
  → buff added
  → appearance modifier active
  → buff removed
  → appearance returns to normal

Delayed consequence

Buff added
  → timer runs
  → loot_on_removal executes
  → next buff/trait/statistic state begins

Conditional effect

Buff is active
  → internal test evaluates current Sim/context
  → only matching branch/modifier applies

Core trait effect

Trait equipped
  → core buff active
  → ongoing modifiers/tests/appearance/autonomy effects

8. How to investigate an unfamiliar buff

Quick reference