diff --git a/core/src/Behavior.cpp b/core/src/Behavior.cpp
index 72e88c5..0969728 100644
--- a/core/src/Behavior.cpp
+++ b/core/src/Behavior.cpp
@@ -309,3 +309,161 @@ BehaviorStatus InverterNode::onTick(BehaviorContext& ctx) {
     return BehaviorStatus::Running;
 }
 
+RepeaterNode::RepeaterNode(std::string name, std::unique_ptr<BehaviorNode> child, int limit,
+                           bool stopWhenChildFails)
+    : DecoratorNode(std::move(name), std::move(child)),
+      repeatLimit(limit),
+      stopOnFailure(stopWhenChildFails) {}
+
+BehaviorStatus RepeaterNode::onTick(BehaviorContext& ctx) {
+    BehaviorStatus status = child().tick(ctx);
+    if (status == BehaviorStatus::Running) return BehaviorStatus::Running;
+    if (status == BehaviorStatus::Failure && stopOnFailure) {
+        completed = 0;
+        return BehaviorStatus::Failure;
+    }
+    ++completed;
+    if (completed >= repeatLimit) {
+        completed = 0;
+        return BehaviorStatus::Success;
+    }
+    return BehaviorStatus::Running;
+}
+
+void RepeaterNode::onReset() { completed = 0; }
+
+RetryUntilSuccessNode::RetryUntilSuccessNode(std::string name, std::unique_ptr<BehaviorNode> child,
+                                             int attemptLimit)
+    : DecoratorNode(std::move(name), std::move(child)), maxAttempts(attemptLimit) {}
+
+BehaviorStatus RetryUntilSuccessNode::onTick(BehaviorContext& ctx) {
+    BehaviorStatus status = child().tick(ctx);
+    if (status == BehaviorStatus::Running) return BehaviorStatus::Running;
+    if (status == BehaviorStatus::Success) {
+        attempts = 0;
+        return BehaviorStatus::Success;
+    }
+    ++attempts;
+    if (attempts >= maxAttempts) {
+        attempts = 0;
+        return BehaviorStatus::Failure;
+    }
+    child().reset();
+    return BehaviorStatus::Running;
+}
+
+void RetryUntilSuccessNode::onReset() { attempts = 0; }
+
+CooldownNode::CooldownNode(std::string name, std::unique_ptr<BehaviorNode> child, int ticks)
+    : DecoratorNode(std::move(name), std::move(child)), cooldownTicks(ticks) {}
+
+BehaviorStatus CooldownNode::onTick(BehaviorContext& ctx) {
+    if (remaining > 0) {
+        --remaining;
+        return BehaviorStatus::Failure;
+    }
+    BehaviorStatus status = child().tick(ctx);
+    if (status != BehaviorStatus::Running) remaining = cooldownTicks;
+    return status;
+}
+
+void CooldownNode::onReset() { remaining = 0; }
+
+TimeLimitNode::TimeLimitNode(std::string name, std::unique_ptr<BehaviorNode> child, int ticks)
+    : DecoratorNode(std::move(name), std::move(child)), limitTicks(ticks) {}
+
+BehaviorStatus TimeLimitNode::onTick(BehaviorContext& ctx) {
+    ++elapsed;
+    BehaviorStatus status = child().tick(ctx);
+    if (status != BehaviorStatus::Running) {
+        elapsed = 0;
+        return status;
+    }
+    if (elapsed >= limitTicks) {
+        elapsed = 0;
+        child().reset();
+        return BehaviorStatus::Failure;
+    }
+    return BehaviorStatus::Running;
+}
+
+void TimeLimitNode::onReset() { elapsed = 0; }
+
+BehaviorTreeStats measureBehaviorTree(const BehaviorNode* root) {
+    BehaviorTreeStats stats;
+    if (root == nullptr) return stats;
+
+    std::vector<std::pair<const BehaviorNode*, int>> pending;
+    pending.push_back({root, 1});
+    while (!pending.empty()) {
+        std::pair<const BehaviorNode*, int> entry = pending.back();
+        pending.pop_back();
+        ++stats.nodeCount;
+        if (entry.second > stats.depth) stats.depth = entry.second;
+        for (int i = 0; i < entry.first->childCount(); ++i) {
+            pending.push_back({entry.first->childAt(i), entry.second + 1});
+        }
+    }
+    stats.withinDepthLimit = stats.depth <= maxBehaviorDepth;
+    return stats;
+}
+
+BehaviorTree::BehaviorTree(std::unique_ptr<BehaviorNode> newRoot) { setRoot(std::move(newRoot)); }
+
+void BehaviorTree::setRoot(std::unique_ptr<BehaviorNode> newRoot) {
+    rootNode = std::move(newRoot);
+    treeStats = measureBehaviorTree(rootNode.get());
+    ticks = 0;
+}
+
+BehaviorStatus BehaviorTree::tick(BehaviorContext& ctx) {
+    if (!structureValid()) return BehaviorStatus::Failure;
+    ++ticks;
+    ++ctx.tick;
+    return rootNode->tick(ctx);
+}
+
+void BehaviorTree::reset() {
+    if (rootNode) rootNode->reset();
+    ticks = 0;
+}
+
+const char* behaviorRoleName(BehaviorRole role) {
+    switch (role) {
+        case BehaviorRole::HostileHunter: return "hostileHunter";
+        case BehaviorRole::GrazingAnimal: return "grazingAnimal";
+        case BehaviorRole::SunAvoider: return "sunAvoider";
+        case BehaviorRole::Count: break;
+    }
+    return "unknown";
+}
+
+BehaviorRole roleForSpecies(Species species) {
+    switch (species) {
+        case Species::Zombie:
+        case Species::Creeper:
+            return BehaviorRole::HostileHunter;
+        case Species::Skeleton:
+            return BehaviorRole::SunAvoider;
+        default:
+            return BehaviorRole::GrazingAnimal;
+    }
+}
+
+ItemId breedingFoodFor(Species species) {
+    switch (species) {
+        case Species::Sheep:
+        case Species::Cow:
+            return ItemId::Bread;
+        case Species::Pig:
+            return ItemId::Apple;
+        default:
+            return ItemId::None;
+    }
+}
+
+bool isBreedingFood(Species species, ItemId held) {
+    ItemId wanted = breedingFoodFor(species);
+    return wanted != ItemId::None && held == wanted;
+}
+