diff --git a/checker/rule.go b/checker/rule.go
index d201dd6..c5c2321 100644
--- a/checker/rule.go
+++ b/checker/rule.go
@@ -9,20 +9,58 @@ import (
 	sdk "git.happydns.org/checker-sdk-go/checker"
 )
 
-// Rule returns a new zonemaster check rule.
-func Rule() sdk.CheckRule {
-	return &zonemasterRule{}
+// Rules returns the full list of CheckRules exposed by the Zonemaster checker.
+// Each rule narrows the Zonemaster results to a single test category so
+// callers can see at a glance which category passed and which did not,
+// instead of squashing every Zonemaster message into a single monolithic
+// state. The Zonemaster-returned severity (INFO/NOTICE/WARNING/ERROR/
+// CRITICAL) is treated as a raw input coming from Zonemaster's own
+// judgement; each rule maps it onto happyDomain's CheckState.Status.
+func Rules() []sdk.CheckRule {
+	return []sdk.CheckRule{
+		dnssecRule(),
+		delegationRule(),
+		consistencyRule(),
+		connectivityRule(),
+		nameserverRule(),
+		syntaxRule(),
+		zoneRule(),
+		addressRule(),
+		basicRule(),
+	}
 }
 
-type zonemasterRule struct{}
+// Rule returns the legacy single-rule view of the Zonemaster checker.
+//
+// Deprecated: use Rules() for per-category CheckRules. This wrapper is kept
+// so existing callers that only expect a single rule keep compiling.
+func Rule() sdk.CheckRule { return &legacyRule{} }
 
-func (r *zonemasterRule) Name() string { return "zonemaster" }
+type legacyRule struct{}
 
-func (r *zonemasterRule) Description() string {
-	return "Runs Zonemaster DNS validation tests against the zone"
+func (r *legacyRule) Name() string { return "zonemaster" }
+
+func (r *legacyRule) Description() string {
+	return "Runs Zonemaster DNS validation tests against the zone (aggregate view)."
 }
 
-func (r *zonemasterRule) ValidateOptions(opts sdk.CheckerOptions) error {
+func (r *legacyRule) ValidateOptions(opts sdk.CheckerOptions) error {
+	return validateZonemasterOptions(opts)
+}
+
+func (r *legacyRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, _ sdk.CheckerOptions) []sdk.CheckState {
+	data, errSt := loadZonemasterData(ctx, obs)
+	if errSt != nil {
+		return []sdk.CheckState{*errSt}
+	}
+	return []sdk.CheckState{summarizeAll(data)}
+}
+
+// ── shared helpers ────────────────────────────────────────────────────────────
+
+// validateZonemasterOptions validates the options accepted by the Zonemaster
+// checker. Shared across rules that implement OptionsValidator.
+func validateZonemasterOptions(opts sdk.CheckerOptions) error {
 	if v, ok := opts["zonemasterAPIURL"]; ok {
 		s, ok := v.(string)
 		if !ok {
@@ -44,16 +82,180 @@ func (r *zonemasterRule) ValidateOptions(opts sdk.CheckerOptions) error {
 	return nil
 }
 
-func (r *zonemasterRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, opts sdk.CheckerOptions) []sdk.CheckState {
+// loadZonemasterData fetches the Zonemaster observation. On error, returns a
+// CheckState the caller should emit to short-circuit its rule.
+func loadZonemasterData(ctx context.Context, obs sdk.ObservationGetter) (*ZonemasterData, *sdk.CheckState) {
 	var data ZonemasterData
 	if err := obs.Get(ctx, ObservationKeyZonemaster, &data); err != nil {
-		return []sdk.CheckState{{
+		return nil, &sdk.CheckState{
 			Status:  sdk.StatusError,
-			Message: fmt.Sprintf("Failed to get Zonemaster data: %v", err),
-			Code:    "zonemaster_error",
+			Message: fmt.Sprintf("failed to load Zonemaster observation: %v", err),
+			Code:    "zonemaster.observation_error",
+		}
+	}
+	return &data, nil
+}
+
+// levelToStatus maps a Zonemaster-returned severity to happyDomain's status.
+// Zonemaster's own judgement is treated as raw input; this is happyDomain's
+// own mapping onto the SDK status enum.
+func levelToStatus(level string) sdk.Status {
+	switch strings.ToUpper(level) {
+	case "CRITICAL", "ERROR":
+		return sdk.StatusCrit
+	case "WARNING":
+		return sdk.StatusWarn
+	case "NOTICE", "INFO":
+		return sdk.StatusInfo
+	case "DEBUG":
+		return sdk.StatusInfo
+	default:
+		return sdk.StatusUnknown
+	}
+}
+
+// worstStatus returns the more severe of two statuses. StatusError always
+// wins because it means "we could not evaluate".
+func worstStatus(a, b sdk.Status) sdk.Status {
+	rank := func(s sdk.Status) int {
+		switch s {
+		case sdk.StatusError:
+			return 6
+		case sdk.StatusCrit:
+			return 5
+		case sdk.StatusWarn:
+			return 4
+		case sdk.StatusInfo:
+			return 2
+		case sdk.StatusOK:
+			return 1
+		default:
+			return 0
+		}
+	}
+	if rank(a) >= rank(b) {
+		return a
+	}
+	return b
+}
+
+// categoryRule is the common shape used by every per-category Zonemaster
+// rule: load the observation, filter messages whose module matches one of
+// the declared names, map Zonemaster severities onto CheckState.Status,
+// and emit a summary state plus one state per WARNING-or-worse message.
+// INFO/NOTICE messages are folded into the summary counts so the state
+// list stays readable.
+type categoryRule struct {
+	name        string
+	description string
+	modules     []string // case-insensitive module names handled by this rule
+}
+
+func (r *categoryRule) Name() string        { return r.name }
+func (r *categoryRule) Description() string { return r.description }
+
+func (r *categoryRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, _ sdk.CheckerOptions) []sdk.CheckState {
+	data, errSt := loadZonemasterData(ctx, obs)
+	if errSt != nil {
+		return []sdk.CheckState{*errSt}
+	}
+
+	matched := filterByModules(data.Results, r.modules)
+	if len(matched) == 0 {
+		return []sdk.CheckState{{
+			Status:  sdk.StatusUnknown,
+			Message: fmt.Sprintf("No %s messages returned by Zonemaster for this zone.", r.name),
+			Code:    r.name + ".not_tested",
 		}}
 	}
 
+	var (
+		critCount, errCount, warnCount, noticeCount, infoCount int
+		worst                                                  = sdk.StatusOK
+		issueStates                                            []sdk.CheckState
+	)
+
+	for _, res := range matched {
+		lvl := strings.ToUpper(res.Level)
+		st := levelToStatus(lvl)
+		worst = worstStatus(worst, st)
+
+		switch lvl {
+		case "CRITICAL":
+			critCount++
+		case "ERROR":
+			errCount++
+		case "WARNING":
+			warnCount++
+		case "NOTICE":
+			noticeCount++
+		default:
+			infoCount++
+		}
+
+		if st == sdk.StatusCrit || st == sdk.StatusWarn {
+			issueStates = append(issueStates, sdk.CheckState{
+				Status:  st,
+				Message: res.Message,
+				Code:    r.name + "." + strings.ToLower(lvl),
+				Subject: res.Testcase,
+				Meta: map[string]any{
+					"module":   res.Module,
+					"testcase": res.Testcase,
+					"level":    lvl,
+				},
+			})
+		}
+	}
+
+	summary := sdk.CheckState{
+		Status: worst,
+		Code:   r.name + ".summary",
+		Meta: map[string]any{
+			"total":    len(matched),
+			"critical": critCount,
+			"error":    errCount,
+			"warning":  warnCount,
+			"notice":   noticeCount,
+			"info":     infoCount,
+		},
+	}
+
+	switch {
+	case critCount+errCount > 0:
+		summary.Message = fmt.Sprintf("%d error(s), %d warning(s) reported by Zonemaster (%d checks).", critCount+errCount, warnCount, len(matched))
+	case warnCount > 0:
+		summary.Message = fmt.Sprintf("%d warning(s) reported by Zonemaster (%d checks).", warnCount, len(matched))
+	default:
+		summary.Status = sdk.StatusOK
+		summary.Message = fmt.Sprintf("No issues reported by Zonemaster (%d checks).", len(matched))
+	}
+
+	return append([]sdk.CheckState{summary}, issueStates...)
+}
+
+// filterByModules returns the subset of results whose Module matches any of
+// the given module names (case-insensitive).
+func filterByModules(results []ZonemasterTestResult, modules []string) []ZonemasterTestResult {
+	if len(modules) == 0 {
+		return nil
+	}
+	set := make(map[string]struct{}, len(modules))
+	for _, m := range modules {
+		set[strings.ToLower(m)] = struct{}{}
+	}
+	var out []ZonemasterTestResult
+	for _, r := range results {
+		if _, ok := set[strings.ToLower(r.Module)]; ok {
+			out = append(out, r)
+		}
+	}
+	return out
+}
+
+// summarizeAll produces the legacy monolithic summary state. Preserved so
+// Rule() keeps behaving as before for callers that still use it.
+func summarizeAll(data *ZonemasterData) sdk.CheckState {
 	var errorCount, warningCount int
 	var criticalMsgs []string
 
@@ -86,27 +288,25 @@ func (r *zonemasterRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter
 			}
 			statusLine += ": " + strings.Join(criticalMsgs[:n], "; ")
 		}
-		return []sdk.CheckState{{
+		return sdk.CheckState{
 			Status:  sdk.StatusCrit,
 			Message: statusLine,
 			Code:    "zonemaster_errors",
 			Meta:    meta,
-		}}
+		}
 	}
-
 	if warningCount > 0 {
-		return []sdk.CheckState{{
+		return sdk.CheckState{
 			Status:  sdk.StatusWarn,
 			Message: fmt.Sprintf("%d warning(s) found", warningCount),
 			Code:    "zonemaster_warnings",
 			Meta:    meta,
-		}}
+		}
 	}
-
-	return []sdk.CheckState{{
+	return sdk.CheckState{
 		Status:  sdk.StatusOK,
 		Message: fmt.Sprintf("All checks passed (%d checks)", len(data.Results)),
 		Code:    "zonemaster_ok",
 		Meta:    meta,
-	}}
+	}
 }
diff --git a/checker/rules_address.go b/checker/rules_address.go
new file mode 100644
index 0000000..8901877
--- /dev/null
+++ b/checker/rules_address.go
@@ -0,0 +1,13 @@
+package checker
+
+import sdk "git.happydns.org/checker-sdk-go/checker"
+
+// addressRule covers Zonemaster's address test module (IP addresses of
+// nameservers, private/reserved ranges, IPv6 coverage).
+func addressRule() sdk.CheckRule {
+	return &categoryRule{
+		name:        "zonemaster.address",
+		description: "Zonemaster address tests (IP addresses of nameservers, private/reserved ranges).",
+		modules:     []string{"address"},
+	}
+}
diff --git a/checker/rules_basic.go b/checker/rules_basic.go
new file mode 100644
index 0000000..3337a97
--- /dev/null
+++ b/checker/rules_basic.go
@@ -0,0 +1,14 @@
+package checker
+
+import sdk "git.happydns.org/checker-sdk-go/checker"
+
+// basicRule covers Zonemaster's basic/system test modules (initial
+// reachability and fundamental pre-conditions for running the other test
+// categories).
+func basicRule() sdk.CheckRule {
+	return &categoryRule{
+		name:        "zonemaster.basic",
+		description: "Zonemaster basic tests (initial reachability and fundamental requirements).",
+		modules:     []string{"basic", "system"},
+	}
+}
diff --git a/checker/rules_connectivity.go b/checker/rules_connectivity.go
new file mode 100644
index 0000000..8808d1a
--- /dev/null
+++ b/checker/rules_connectivity.go
@@ -0,0 +1,13 @@
+package checker
+
+import sdk "git.happydns.org/checker-sdk-go/checker"
+
+// connectivityRule covers Zonemaster's connectivity test module (UDP/TCP
+// reachability of authoritative servers, AS diversity).
+func connectivityRule() sdk.CheckRule {
+	return &categoryRule{
+		name:        "zonemaster.connectivity",
+		description: "Zonemaster connectivity tests (reachability of authoritative servers over UDP/TCP, AS diversity).",
+		modules:     []string{"connectivity"},
+	}
+}
diff --git a/checker/rules_consistency.go b/checker/rules_consistency.go
new file mode 100644
index 0000000..24db2b5
--- /dev/null
+++ b/checker/rules_consistency.go
@@ -0,0 +1,13 @@
+package checker
+
+import sdk "git.happydns.org/checker-sdk-go/checker"
+
+// consistencyRule covers Zonemaster's consistency test module (SOA serial,
+// NS set, zone content identical across authoritative servers).
+func consistencyRule() sdk.CheckRule {
+	return &categoryRule{
+		name:        "zonemaster.consistency",
+		description: "Zonemaster consistency tests (SOA serial, NS set, zone content across servers).",
+		modules:     []string{"consistency"},
+	}
+}
diff --git a/checker/rules_delegation.go b/checker/rules_delegation.go
new file mode 100644
index 0000000..0c6e156
--- /dev/null
+++ b/checker/rules_delegation.go
@@ -0,0 +1,13 @@
+package checker
+
+import sdk "git.happydns.org/checker-sdk-go/checker"
+
+// delegationRule covers Zonemaster's delegation test module (parent/child NS
+// agreement, glue correctness, referral integrity).
+func delegationRule() sdk.CheckRule {
+	return &categoryRule{
+		name:        "zonemaster.delegation",
+		description: "Zonemaster delegation tests (parent/child NS agreement, glue, referrals).",
+		modules:     []string{"delegation"},
+	}
+}
diff --git a/checker/rules_dnssec.go b/checker/rules_dnssec.go
new file mode 100644
index 0000000..e3b5054
--- /dev/null
+++ b/checker/rules_dnssec.go
@@ -0,0 +1,13 @@
+package checker
+
+import sdk "git.happydns.org/checker-sdk-go/checker"
+
+// dnssecRule covers Zonemaster's DNSSEC test module (signatures, NSEC/NSEC3,
+// DS/DNSKEY coherence, algorithm posture).
+func dnssecRule() sdk.CheckRule {
+	return &categoryRule{
+		name:        "zonemaster.dnssec",
+		description: "Zonemaster DNSSEC tests (signatures, NSEC/NSEC3, DS/DNSKEY coherence).",
+		modules:     []string{"dnssec"},
+	}
+}
diff --git a/checker/rules_nameserver.go b/checker/rules_nameserver.go
new file mode 100644
index 0000000..e7ea6b4
--- /dev/null
+++ b/checker/rules_nameserver.go
@@ -0,0 +1,13 @@
+package checker
+
+import sdk "git.happydns.org/checker-sdk-go/checker"
+
+// nameserverRule covers Zonemaster's nameserver test module (server
+// behaviour, EDNS posture, unknown RR handling).
+func nameserverRule() sdk.CheckRule {
+	return &categoryRule{
+		name:        "zonemaster.nameserver",
+		description: "Zonemaster nameserver tests (server behaviour, EDNS, unknown RR handling).",
+		modules:     []string{"nameserver"},
+	}
+}
diff --git a/checker/rules_syntax.go b/checker/rules_syntax.go
new file mode 100644
index 0000000..3daacad
--- /dev/null
+++ b/checker/rules_syntax.go
@@ -0,0 +1,13 @@
+package checker
+
+import sdk "git.happydns.org/checker-sdk-go/checker"
+
+// syntaxRule covers Zonemaster's syntax test module (domain name syntax,
+// hostname legality).
+func syntaxRule() sdk.CheckRule {
+	return &categoryRule{
+		name:        "zonemaster.syntax",
+		description: "Zonemaster syntax tests (domain name syntax, hostname legality).",
+		modules:     []string{"syntax"},
+	}
+}
diff --git a/checker/rules_zone.go b/checker/rules_zone.go
new file mode 100644
index 0000000..1aaaae7
--- /dev/null
+++ b/checker/rules_zone.go
@@ -0,0 +1,13 @@
+package checker
+
+import sdk "git.happydns.org/checker-sdk-go/checker"
+
+// zoneRule covers Zonemaster's zone test module (SOA values, MX presence,
+// mandatory records at the apex).
+func zoneRule() sdk.CheckRule {
+	return &categoryRule{
+		name:        "zonemaster.zone",
+		description: "Zonemaster zone tests (SOA values, MX presence, mandatory records).",
+		modules:     []string{"zone"},
+	}
+}