Normative BDI Agent Architecture
Use this skill when an agent must stay aware of multiple norms, decide which ones to adopt into action, and explain why a deliberate violation was less bad than the alternatives.
When to Use
- Multiple rules, obligations, prohibitions, or stakeholder demands cannot all be satisfied together.
- An agent must distinguish knowing that a norm exists from actually choosing to follow it.
- A system needs to justify why it violated one rule to satisfy another higher-stakes commitment.
- You need a consequence-based alternative to brittle hard-coded priority lists.
- A BDI architecture needs a principled way to integrate normative reasoning without turning norms into absolute overrides.
NOT for Boundaries
This skill is not the primary tool for:
- Fixed priority hierarchies where the correct precedence never changes with context.
- Pure constraint satisfaction where any satisfying solution is good enough and norm violation is out of scope.
- Regulatory or ethical environments that require literal non-violation regardless of consequences.
- Toy rule engines that do not maintain beliefs, commitments, or explanations of deliberate violations.
Core Mental Models
Recognition Is Not Internalization
Keep the Abstract Norm Base separate from the Norm Instance Base. The agent can detect a norm without adopting it. That separation is what allows deliberate, explainable non-compliance instead of accidental ignorance.
Three Consistency States
- Strong inconsistency: no plan can satisfy both commitments.
- Weak consistency: some plans work, but future flexibility shrinks.
- Strong consistency: all relevant plans remain compatible.
The weak-consistency case is where most real design judgment lives.
Consequence Ranking
When norms conflict, compare coherent bundles of commitments by their worst downstream consequence. The point is not maximizing average goodness; it is choosing the least-bad worst case among incompatible futures.
Norms as Hypothetical Desires
Adopted obligations and prohibitions become defeasible pressures inside the BDI machinery rather than a separate override system. That keeps normative reasoning inside the same deliberative loop as ordinary goal pursuit.
Decision Points
See the adoption and conflict flow in diagrams/01_flowchart_decision-points.md.
flowchart TD
A[Norm detected] --> B{Groundable in current beliefs?}
B -->|No| C[Keep abstract and monitor]
B -->|Yes| D[Check consistency]
D -->|Strongly inconsistent| E[Compare conflict bundles by worst consequence]
D -->|Weakly consistent| F[Evaluate flexibility cost]
D -->|Strongly consistent| G[Adopt norm]
E --> H[Choose least-bad worst case]
F --> I{Adoption still worth it?}
I -->|Yes| G
I -->|No| J[Reject or defer]
H --> G
1. Decide Whether to Adopt a Norm
- If a new norm is strongly inconsistent with current commitments, adoption requires dropping or revising something else.
- If it is weakly consistent, make the flexibility cost explicit before adopting it.
- If it is strongly consistent, adoption is low-risk and should usually be automatic.
2. Decide How to Resolve a Conflict
- Generate maximal non-conflicting subsets rather than comparing norms one-by-one in isolation.
- Build plans for each subset and identify the worst consequence in each future.
- Choose the subset whose worst case is least bad, then record the reason for the chosen violation.
3. Decide When to Instantiate an Abstract Norm
- Instantiate only when current beliefs can bind variables and satisfy activation conditions.
- Keep unresolved norms visible when knowledge is incomplete instead of pretending they do not apply.
- Re-evaluate pending abstract norms after meaningful belief updates.
Failure Modes
1. Over-Adoption Deadlock
Symptoms: the agent keeps internalizing norms until no feasible action remains.
Detection rule: the active action space shrinks faster than conflicts are resolved.
Recovery: force a consistency review before any additional norm enters the Norm Instance Base.
2. Hidden Violation
Symptoms: the agent violates a norm but cannot state that it chose to do so.
Detection rule: post-hoc explanations omit the rejected norm or treat the violation as if it never existed.
Recovery: persist rejected-but-recognized norms and log the winning consequence comparison.
3. Binary Consistency Collapse
Symptoms: adoption logic treats every norm as either fully compatible or impossible.
Detection rule: weak consistency never appears in the architecture or logs.
Recovery: add an explicit weak-consistency branch and model flexibility loss directly.
4. Fixed-Priority Brittleness
Symptoms: the same global priority stack produces obviously wrong choices in edge cases.
Detection rule: conflict outcomes change only when the priority table changes, never when consequences change.
Recovery: move from rigid precedence to subset generation plus consequence ranking.
5. Norm Side-Channel Architecture
Symptoms: norm handling lives in a separate enforcement module that overrides BDI deliberation late in execution.
Detection rule: norm logic cannot be explained using beliefs, desires, and intentions.
Recovery: transform adopted norms into internal deliberative pressures and route them through the main architecture.
Worked Examples
Example 1: Privacy vs. Personalization
A service agent knows a norm prohibiting direct use of customer-level data and an obligation to improve the user experience. The system finds weak consistency: aggregate behavioral summaries preserve most personalization while limiting privacy harm. The skill keeps both norms visible, instantiates only the aggregate-safe obligation, and records why direct data use was rejected.
Example 2: Robot and Baby
A caretaker robot faces an obligation to keep a baby alive and a prohibition against developing love for humans. No plan satisfies both. The skill generates two coherent subsets, compares the worst consequences, and deliberately violates the design prohibition because death is a worse outcome than the forbidden attachment. The violation is explicit and reportable.
Quality Gates
Reference Files
| File | Load when |
|---|
references/separation-of-norm-recognition-and-norm-internalization.md | Designing ANB vs. NIB boundaries |
references/three-types-of-consistency-for-norm-adoption.md | Implementing adoption checks and flexibility-cost logic |
references/normative-conflict-resolution-through-consequence-ranking.md | Building or reviewing consequence-based conflict resolution |
references/norm-instantiation-through-belief-grounding.md | Grounding abstract norms into context-specific instances |
references/maximal-non-conflicting-subsets-for-action-selection.md | Computing coherent option bundles under conflict |
references/desire-internalization-as-norm-adoption-mechanism.md | Integrating norms into BDI desire and intention handling |
Anti-Patterns
- Hard-coding a single priority order and calling that "ethics."
- Auto-adopting every detected norm and discovering contradictions only at execution time.
- Treating weak consistency as if it were the same as strong consistency.
- Comparing violations by average utility while ignoring catastrophic worst cases.