Enforce quest- and world's rules before starting a duel.

E.g. no Vintage cards allowed in player's deck while in Random Standard world.

forge-game/src/main/java/forge/game/GameFormat.java

@@ -245,27 +245,65 @@ public class GameFormat implements Comparable<GameFormat> {
     }
     
     private boolean isPoolLegal(final CardPool allCards) {
-        for (Entry<PaperCard, Integer> poolEntry : allCards) {
-            if (!filterRules.apply(poolEntry.getKey())) {
-                return false; //all cards in deck must pass card predicate to pass deck predicate
-            }
-        }
-        
-        if(!restrictedCardNames_ro.isEmpty() || restrictedLegendary ) {
-            for (Entry<PaperCard, Integer> poolEntry : allCards) {
-                if( poolEntry.getValue().intValue() > 1 && (restrictedCardNames_ro.contains(poolEntry.getKey().getName())
-                    || (poolEntry.getKey().getRules().getType().isLegendary()
-                        && !poolEntry.getKey().getRules().getType().isPlaneswalker() && restrictedLegendary)))
-                    return false;
-            }
-        }
-        return true;
+        return getPoolLegalityProblem(allCards) == null;
     }
     
     public boolean isDeckLegal(final Deck deck) {
         return isPoolLegal(deck.getAllCardsInASinglePool());
     }
 
+    private String getPoolLegalityProblem(final CardPool allCards) {
+        // Check filter rules
+        {
+            final List<PaperCard> erroneousCI = new ArrayList<>();
+            for (Entry<PaperCard, Integer> poolEntry : allCards) {
+                if (!filterRules.apply(poolEntry.getKey())) {
+                    erroneousCI.add(poolEntry.getKey());
+                }
+            }
+            if (erroneousCI.size() > 0) {
+                final StringBuilder sb = new StringBuilder("contains the following illegal cards:\n");
+                for (final PaperCard cp : erroneousCI) {
+                    sb.append("\n").append(cp.getName());
+                }
+                return sb.toString();
+            }
+        }
+        // Check number of restricted and legendary-restricted cards
+        if(!restrictedCardNames_ro.isEmpty() || restrictedLegendary ) {
+            final List<PaperCard> erroneousRestricted = new ArrayList<>();
+            for (Entry<PaperCard, Integer> poolEntry : allCards) {
+                boolean isRestricted = restrictedCardNames_ro.contains(poolEntry.getKey().getName());
+                boolean isLegendaryNonPlaneswalker = poolEntry.getKey().getRules().getType().isLegendary()
+                        && !poolEntry.getKey().getRules().getType().isPlaneswalker() && restrictedLegendary;
+                if( poolEntry.getValue() > 1 && (isRestricted || isLegendaryNonPlaneswalker)) {
+                    erroneousRestricted.add(poolEntry.getKey());
+                }
+            }
+            if (erroneousRestricted.size() > 0) {
+                final StringBuilder sb = new StringBuilder("contains more than one copy of the following restricted cards:\n");
+                for (final PaperCard cp : erroneousRestricted) {
+                    sb.append("\n").append(cp.getName());
+                }
+                return sb.toString();
+            }
+        }
+        return null;
+    }
+
+    /**
+     * Check the conformance of a deck in this GameFormat.
+     * Will check each card's set legality, and ensure no banned and max one of each restricted card exists.
+     * @param deck The deck to analyse
+     * @return An error string describing the errors and associated cards, or null if no errors
+     */
+    public String getDeckConformanceProblem(final Deck deck) {
+        if (deck == null) {
+            return "is not selected";
+        }
+        return getPoolLegalityProblem(deck.getAllCardsInASinglePool());
+    }
+
     @Override
     public String toString() {
         return this.name;

forge-gui/src/main/java/forge/gamemodes/quest/QuestUtil.java

@@ -664,7 +664,7 @@ public class QuestUtil {
         }
 
         if (FModel.getPreferences().getPrefBoolean(FPref.ENFORCE_DECK_LEGALITY)) {
-            final String errorMessage = getDeckConformanceProblems(deck);
+            final String errorMessage = getDeckConformanceProblemsBeforeGame(deck);
             if (null != errorMessage) {
                 SOptionPane.showErrorDialog(localizer.getMessage("lblInvalidDeckDesc").replace("%n",errorMessage), "Invalid Deck");
                 return false;
@@ -674,9 +674,15 @@ public class QuestUtil {
         return true;
     }
 
-    public static String getDeckConformanceProblems(Deck deck){
+    public static String getDeckConformanceProblemsBeforeGame(Deck deck){
+        // Challenges with fixed decks override conformance settings
+        if(event instanceof QuestEventChallenge && ((QuestEventChallenge) event).getHumanDeck() != null)
+            return null;
+
+        //Check quest mode's generic deck construction rules: minimum cards in deck, sideboard etc
         String errorMessage = GameType.Quest.getDeckFormat().getDeckConformanceProblem(deck);
 
+        //Check the quest mode's generic deck construction rules: minimum cards in deck, sideboard etc
         if(errorMessage != null) return errorMessage; //return immediately if the deck does not conform to quest requirements
 
         //Check for all applicable deck construction rules per this quests's saved DeckConstructionRules enum
@@ -685,6 +691,11 @@ public class QuestUtil {
                 errorMessage = GameType.Commander.getDeckFormat().getDeckConformanceProblem(deck);
                 break;
         }
+        if(errorMessage != null) return errorMessage;
+
+        //Check for this quest- and World's deck construction rules: allowed sets, banned/restricted cards etc
+        if(FModel.getQuest().getFormat() != null)
+            errorMessage = FModel.getQuest().getFormat().getDeckConformanceProblem(deck);
 
         return errorMessage;
     }