diff --git a/src/applications/project/controller/PhabricatorProjectArchiveController.php b/src/applications/project/controller/PhabricatorProjectArchiveController.php
--- a/src/applications/project/controller/PhabricatorProjectArchiveController.php
+++ b/src/applications/project/controller/PhabricatorProjectArchiveController.php
@@ -52,7 +52,46 @@
       $button = pht('Activate Project');
     } else {
       $title = pht('Really archive project?');
-      $body = pht('This project will be moved to the archive.');
+
+      // Make dialog mention Herald rules which use the project in conditions
+      $affected_rules = id(new HeraldRuleQuery())
+        ->setViewer(PhabricatorUser::getOmnipotentUser())
+        ->withDisabled(false)
+        ->withAffectedObjectPHIDs(array($project->getPHID()))
+        ->execute();
+      if ($affected_rules) {
+        $affected_rules = array_keys($affected_rules);
+        sort($affected_rules);
+        $prefixed_rules = array_map(function ($key) {
+          return 'H'.$key;
+        }, $affected_rules);
+        $prefixed_rules = implode(', ', $prefixed_rules);
+
+        // Render a link if acting user has Herald "Can Use Application" rights
+        $can_herald = PhabricatorApplication::isClassInstalledForViewer(
+          'PhabricatorHeraldApplication',
+          $viewer);
+        if ($can_herald) {
+          $affected_rules = implode(',', $affected_rules);
+          $herald_uri = new PhutilURI(
+            PhabricatorEnv::getEnvConfig('phabricator.base-uri').
+            '/herald/?ids='.$affected_rules.'#R');
+          $herald_query_uri = phutil_tag('a', array(
+            'href' => $herald_uri,
+            'target' => '_blank',
+            ),
+            $prefixed_rules);
+          $body = pht('This project will be moved to the archive. Herald '.
+            'rule(s) %s use this project in their conditions and may require '.
+            'changes.', $herald_query_uri);
+        } else {
+          $body = pht('This project will be moved to the archive. Herald '.
+            'rule(s) %s use this project in their conditions and may require '.
+            'changes. Please inform your Herald magician.', $prefixed_rules);
+        }
+      } else {
+        $body = pht('This project will be moved to the archive.');
+      }
       $button = pht('Archive Project');
     }