diff --git a/src/storm/shields/AbstractShield.cpp b/src/storm/shields/AbstractShield.cpp
index 62944b7d9..309666aa9 100644
--- a/src/storm/shields/AbstractShield.cpp
+++ b/src/storm/shields/AbstractShield.cpp
@@ -5,7 +5,7 @@ namespace tempest {
     namespace shields {
 
         template<typename ValueType, typename IndexType>
-        AbstractShield<ValueType, IndexType>::AbstractShield(std::vector<IndexType> const& rowGroupIndices, std::vector<ValueType> const& choiceValues, std::shared_ptr<storm::logic::ShieldExpression const> const& shieldingExpression, boost::optional<storm::storage::BitVector> coalitionStates) : rowGroupIndices(rowGroupIndices), choiceValues(choiceValues), shieldingExpression(shieldingExpression), coalitionStates(coalitionStates) {
+        AbstractShield<ValueType, IndexType>::AbstractShield(std::vector<IndexType> const& rowGroupIndices, std::vector<ValueType> const& choiceValues, std::shared_ptr<storm::logic::ShieldExpression const> const& shieldingExpression, storm::storage::BitVector relevantStates, boost::optional<storm::storage::BitVector> coalitionStates) : rowGroupIndices(rowGroupIndices), choiceValues(choiceValues), shieldingExpression(shieldingExpression), relevantStates(relevantStates), coalitionStates(coalitionStates) {
             // Intentionally left empty.
         }
 
diff --git a/src/storm/shields/AbstractShield.h b/src/storm/shields/AbstractShield.h
index cc7fe9ca6..0ba34b56a 100644
--- a/src/storm/shields/AbstractShield.h
+++ b/src/storm/shields/AbstractShield.h
@@ -3,9 +3,12 @@
 #include <boost/optional.hpp>
 #include <iostream>
 #include <string>
+#include <memory>
 
 #include "storm/storage/Scheduler.h"
+#include "storm/storage/SchedulerChoice.h"
 #include "storm/storage/BitVector.h"
+#include "storm/storage/Distribution.h"
 
 #include "storm/logic/ShieldExpression.h"
 
@@ -31,14 +34,21 @@ namespace tempest {
             std::string getClassName() const;
 
         protected:
-            AbstractShield(std::vector<IndexType> const& rowGroupIndices, std::vector<ValueType> const& choiceValues, std::shared_ptr<storm::logic::ShieldExpression const> const& shieldingExpression, boost::optional<storm::storage::BitVector> coalitionStates);
+            AbstractShield(std::vector<IndexType> const& rowGroupIndices, std::vector<ValueType> const& choiceValues, std::shared_ptr<storm::logic::ShieldExpression const> const& shieldingExpression, storm::storage::BitVector relevantStates, boost::optional<storm::storage::BitVector> coalitionStates);
 
             std::vector<index_type> rowGroupIndices;
             std::vector<value_type> choiceValues;
 
             std::shared_ptr<storm::logic::ShieldExpression const> shieldingExpression;
 
+            storm::storage::BitVector relevantStates;
+
             boost::optional<storm::storage::BitVector> coalitionStates;
         };
+
+        template<typename ValueType, typename IndexType>
+        bool allowedValue(ValueType const& max, ValueType const& v, std::shared_ptr<storm::logic::ShieldExpression const> const shieldExpression) {
+            return shieldExpression->isRelative() ? v >= shieldExpression->getValue() * max : v >= shieldExpression->getValue();
+        }
     }
 }
diff --git a/src/storm/shields/PreSafetyShield.cpp b/src/storm/shields/PreSafetyShield.cpp
index 7cb944299..a87aa940b 100644
--- a/src/storm/shields/PreSafetyShield.cpp
+++ b/src/storm/shields/PreSafetyShield.cpp
@@ -1,22 +1,45 @@
 #include "storm/shields/PreSafetyShield.h"
 
+#include <algorithm>
+
 namespace tempest {
     namespace shields {
 
         template<typename ValueType, typename IndexType>
-        PreSafetyShield<ValueType, IndexType>::PreSafetyShield(std::vector<IndexType> const& rowGroupIndices, std::vector<ValueType> const& choiceValues, std::shared_ptr<storm::logic::ShieldExpression const> const& shieldingExpression, boost::optional<storm::storage::BitVector> coalitionStates) : AbstractShield<ValueType, IndexType>(rowGroupIndices, choiceValues, shieldingExpression, coalitionStates) {
+        PreSafetyShield<ValueType, IndexType>::PreSafetyShield(std::vector<IndexType> const& rowGroupIndices, std::vector<ValueType> const& choiceValues, std::shared_ptr<storm::logic::ShieldExpression const> const& shieldingExpression, storm::storage::BitVector relevantStates, boost::optional<storm::storage::BitVector> coalitionStates) : AbstractShield<ValueType, IndexType>(rowGroupIndices, choiceValues, shieldingExpression, relevantStates, coalitionStates) {
             // Intentionally left empty.
         }
 
         template<typename ValueType, typename IndexType>
         storm::storage::Scheduler<ValueType> PreSafetyShield<ValueType, IndexType>::construct() {
-            for(auto const& x: this->rowGroupIndices) {
-                STORM_LOG_DEBUG(x << ", ");
+            storm::storage::Scheduler<ValueType> shield(this->rowGroupIndices.size());
+            STORM_LOG_DEBUG(this->rowGroupIndices.size());
+            STORM_LOG_DEBUG(this->relevantStates);
+            for(auto const& x : this->choiceValues) {
+                STORM_LOG_DEBUG(x << ",");
             }
-            for(auto const& x: this->choiceValues) {
-                STORM_LOG_DEBUG(x << ", ");
+            auto choice_it = this->choiceValues.begin();
+            for(uint state = 0; state < this->rowGroupIndices.size() - 1; state++) {
+                if(this->relevantStates.get(state)) {
+                    uint rowGroupSize = this->rowGroupIndices[state + 1] - this->rowGroupIndices[state];
+                    STORM_LOG_DEBUG("rowGroupSize: " << rowGroupSize);
+                    storm::storage::Distribution<ValueType, IndexType> actionDistribution;
+                    ValueType maxProbability = *std::max_element(this->choiceValues.begin(), this->choiceValues.begin() + rowGroupSize);
+                    for(uint choice = 0; choice < rowGroupSize; choice++, choice_it++) {
+                        if(allowedValue<ValueType, IndexType>(maxProbability, *choice_it, this->shieldingExpression)) {
+                            actionDistribution.addProbability(choice, *choice_it);
+                            STORM_LOG_DEBUG("Adding " << *choice_it << " to dist");
+                        }
+                    }
+                    actionDistribution.normalize();
+                    shield.setChoice(storm::storage::SchedulerChoice<ValueType>(actionDistribution), state);
+                    STORM_LOG_DEBUG("SchedulerChoice: " << storm::storage::SchedulerChoice<ValueType>(actionDistribution));
+
+                } else {
+                    shield.setChoice(storm::storage::Distribution<ValueType, IndexType>(), state);
+                }
             }
-            STORM_LOG_ASSERT(false, "construct NYI");
+            return shield;
         }
         // Explicitly instantiate appropriate
         template class PreSafetyShield<double, typename storm::storage::SparseMatrix<double>::index_type>;
diff --git a/src/storm/shields/PreSafetyShield.h b/src/storm/shields/PreSafetyShield.h
index 0dbcb6906..c962bb0d1 100644
--- a/src/storm/shields/PreSafetyShield.h
+++ b/src/storm/shields/PreSafetyShield.h
@@ -8,7 +8,7 @@ namespace tempest {
         template<typename ValueType, typename IndexType>
         class PreSafetyShield : public AbstractShield<ValueType, IndexType> {
         public:
-            PreSafetyShield(std::vector<IndexType> const& rowGroupIndices, std::vector<ValueType> const& choiceValues, std::shared_ptr<storm::logic::ShieldExpression const> const& shieldingExpression, boost::optional<storm::storage::BitVector> coalitionStates);
+            PreSafetyShield(std::vector<IndexType> const& rowGroupIndices, std::vector<ValueType> const& choiceValues, std::shared_ptr<storm::logic::ShieldExpression const> const& shieldingExpression, storm::storage::BitVector relevantStates, boost::optional<storm::storage::BitVector> coalitionStates);
             storm::storage::Scheduler<ValueType> construct();
         };
     }
diff --git a/src/storm/shields/shield-handling.h b/src/storm/shields/shield-handling.h
index a53c7e8f6..be3b1ce88 100644
--- a/src/storm/shields/shield-handling.h
+++ b/src/storm/shields/shield-handling.h
@@ -14,12 +14,13 @@
 
 #include "storm/exceptions/InvalidArgumentException.h"
 
+
 namespace tempest {
     namespace shields {
         template<typename ValueType, typename IndexType = storm::storage::sparse::state_type>
-        storm::storage::Scheduler<ValueType> createShield(std::vector<IndexType> const& rowGroupIndices, std::vector<ValueType> const& choiceValues, std::shared_ptr<storm::logic::ShieldExpression const> const& shieldingExpression, boost::optional<storm::storage::BitVector> coalitionStates) {
+        storm::storage::Scheduler<ValueType> createShield(std::vector<IndexType> const& rowGroupIndices, std::vector<ValueType> const& choiceValues, std::shared_ptr<storm::logic::ShieldExpression const> const& shieldingExpression, storm::storage::BitVector relevantStates, boost::optional<storm::storage::BitVector> coalitionStates) {
             if(shieldingExpression->isPreSafetyShield()) {
-                PreSafetyShield<ValueType, IndexType> shield(rowGroupIndices, choiceValues, shieldingExpression, coalitionStates);
+                PreSafetyShield<ValueType, IndexType> shield(rowGroupIndices, choiceValues, shieldingExpression, relevantStates, coalitionStates);
                 return shield.construct();
             } else if(shieldingExpression->isPostSafetyShield()) {
                 STORM_LOG_THROW(false, storm::exceptions::InvalidArgumentException, "Cannot create post safety shields yet");