Psyringe - introducing new ability: cantBeBlockedBy(T). T can be any targez specification, like "wall", "creature[flying]", etc. See added cards for examples. Note: This ability currently has the same restrictions as "protection from(T)", i.e. it can't be used in activated abilities or instants/sorceries. It *can* be used for creatures,auras, and other continuous abilities (e.g. an enchantment which grants "unblockable by walls" to all rats should be possible, although I didn't test that). There are 47 cards which use the phrase "can't be blocked by", so we should be able to get another fair mount of cards out of that.

Notes to programmers:
1. This feature uses an awful lot of copy-pasta, using "protetcion from()" as a base. While I'm learning the architecture, it's easier for me to have a dedicated single-purpose piece of code to work with, than trying to create multi-purpose code. I'm aware that this isn't a very elegant approach though, and I hope to be able to refactor additions like this into multi-purpose code once I have a better understanding of the architecture as a whole.

2. Please check the questions I'll add in my next code comments, specifically about AI integration and activated abilities / instants / sorceries.

3. I did have a crash (with the debugger complaining about stack corruption around the cd variable) during testing. I wasn't able to reproduce it though. I did have to clean the solution in-between when I updated to the primitives system, so perhaps there was this cleaning solved whatever corruption was in my files. I'm mentioning the issue in case someone has an idea on where my code might be risky (I'm still probne to making beginners mistakes).

projects/mtg/bin/Res/sets/10E/_cards.dat

@@ -1216,6 +1216,19 @@ type=Artifact
 mana={4}
 [/card]
 [card]
+text=Juggernaut attacks each turn if able. Juggernaut can't be blocked by Walls.
+auto=cantbeblockedby(wall)
+abilities=mustattack
+id=135240
+name=Juggernaut
+rarity=U
+type=Artifact Creature
+mana={4}
+power=5
+subtype=Juggernaut
+toughness=3
+[/card]
+[card]
 text=Haste (This creature can attack and {T} as soon as it comes under your control.)  {T}: Kamahl, Pit Fighter deals 3 damage to target creature or player.
 abilities=haste,legendary
 auto={T}:Damage:3 target(creature,player)

projects/mtg/bin/Res/sets/10E/todo.dat

@@ -486,20 +486,6 @@ type=Instant
 mana={1}{R}
 [/card]
 [card]
-text=Juggernaut attacks each turn if able. Juggernaut can't be blocked by Walls.
-id=135240
-name=Juggernaut
-rarity=U
-color=Artifact
-type=Artifact Creature
-mana={4}
-power=5
-abilities=mustattack
-auto=cantbeblockedby(wall)
-subtype=Juggernaut
-toughness=3
-[/card]
-[card]
 text=Karplusan Strider can't be the target of blue or black spells.
 id=129911
 name=Karplusan Strider

projects/mtg/bin/Res/sets/DIS/_cards.dat

@@ -110,6 +110,18 @@ toughness=9
 abilities=trample
 [/card]
 [card]
+id=107526
+name=Gnat Alley Creeper
+mana={2}{R}
+type=Creature
+subtype=Human Rogue
+power=3
+toughness=1
+text=Gnat Alley Creeper can't be blocked by creatures with flying.
+auto=cantbeblockedby(creature[flying])
+rarity=U
+[/card]
+[card]
 text={T}, Sacrifice Haazda Exonerator: Destroy target Aura.
 id=107467
 name=Haazda Exonerator

projects/mtg/bin/Res/sets/DIS/todo.dat

@@ -1,6 +1,6 @@
 [card]
 id=111192
-name=ÁEhermage's Touch
+name=AEthermage's Touch
 mana={2}{W}{U}
 type=Instant
 text=Reveal the top four cards of your library. You may put a creature card from among them onto the battlefield. It has "At the beginning of your end step, return this creature to its owner's hand." Then put the rest of the cards revealed this way on the bottom of your library in any order.
@@ -468,17 +468,6 @@ text={T}: Add {1} to your mana pool. {T}, Sacrifice Ghost Quarter: Destroy targe
 rarity=U
 [/card]
 [card]
-id=107526
-name=Gnat Alley Creeper
-mana={2}{R}
-type=Creature
-subtype=Human Rogue
-power=3
-toughness=1
-text=Gnat Alley Creeper can't be blocked by creatures with flying.
-rarity=U
-[/card]
-[card]
 id=107542
 name=Gobhobbler Rats
 mana={B}{R}

projects/mtg/bin/Res/sets/DRK/_cards.dat

@@ -522,6 +522,15 @@ mana={0}
 type=Artifact
 [/card]
 [card]
+id=1725
+name=Tower of Coireall
+mana={2}
+type=Artifact
+text={T}: Target creature can't be blocked by Walls this turn.
+auto={T}:cantbeblockedby(wall) target(creature)
+rarity=U
+[/card]
+[card]
 text=Water Wurm gets +0/+1 as long as an opponent controls an Island.
 id=1764
 name=Water Wurm

projects/mtg/bin/Res/sets/DRK/todo.dat

@@ -553,14 +553,6 @@ text=At the beginning of your upkeep, The Fallen deals 1 damage to each opponent
 rarity=U
 [/card]
 [card]
-id=1725
-name=Tower of Coireall
-mana={2}
-type=Artifact
-text={T}: Target creature can't be blocked by Walls this turn.
-rarity=U
-[/card]
-[card]
 id=1779
 name=Tracker
 mana={2}{G}

projects/mtg/bin/Res/sets/DST/_cards.dat

@@ -231,10 +231,7 @@ subtype=Juggernaut
 power=5
 toughness=3
 text=Juggernaut attacks each turn if able. Juggernaut can't be blocked by Walls.
-# Following line is not entirely correct: Walls cannot target
-# Juggernaut although they should be able to. But it's hard to
-# find a case where this difference actually matters.
-auto=protection from(wall)
+auto=cantbeblockedby(wall)
 abilities=mustattack
 rarity=U
 [/card]

projects/mtg/bin/Res/sets/PLC/_cards.dat

@@ -133,6 +133,18 @@ power=2
 toughness=2
 [/card]
 [card]
+id=110501
+name=Dust Corona
+mana={R}
+type=Enchantment
+subtype=Aura
+text=Enchant creature -- Enchanted creature gets +2/+0 and can't be blocked by creatures with flying.
+target=creature
+auto=2/0
+auto=cantbeblockedby(creatures[flying])
+rarity=C
+[/card]
+[card]
 text=Enchant creature You control enchanted creature. At the beginning of your upkeep, enchanted creature deals 1 damage to its owner.
 target=creature
 auto=@each my upkeep:life:-1 opponent

projects/mtg/bin/Res/sets/PLC/todo.dat

@@ -11,7 +11,7 @@ rarity=R
 [/card]
 [card]
 id=124504
-name=ÁEher Membrane
+name=AEther Membrane
 mana={1}{R}{R}
 type=Creature
 subtype=Wall
@@ -278,15 +278,6 @@ text=Protection from green At the beginning of the end step, if Dunerider Outlaw
 rarity=U
 [/card]
 [card]
-id=110501
-name=Dust Corona
-mana={R}
-type=Enchantment
-subtype=Aura
-text=Enchant creature Enchanted creature gets +2/+0 and can't be blocked by creatures with flying.
-rarity=C
-[/card]
-[card]
 id=124343
 name=Dust Elemental
 mana={2}{W}{W}

projects/mtg/bin/Res/sets/RV/_cards.dat

@@ -1189,6 +1189,19 @@ mana={4}
 type=Artifact
 [/card]
 [card]
+text=Juggernaut attacks each turn if able.     Juggernaut can't be blocked by Walls.
+auto=cantbeblockedby(wall)
+abilities=mustattack
+id=1120
+name=Juggernaut
+rarity=U
+type=Artifact Creature
+mana={4}
+power=5
+subtype=Juggernaut
+toughness=3
+[/card]
+[card]
 text=Target creature gains flying until end of turn.
 target=creature
 auto=flying

projects/mtg/bin/Res/sets/RV/todo.dat

@@ -195,18 +195,6 @@ type=Artifact
 mana={4}
 [/card]
 [card]
-text=Juggernaut attacks each turn if able.     Juggernaut can't be blocked by Walls.
-id=1120
-name=Juggernaut
-rarity=U
-color=Artifact
-type=Artifact Creature
-mana={4}
-power=5
-subtype=Juggernaut
-toughness=3
-[/card]
-[card]
 text=You have no maximum hand size.     If an effect causes you to discard a card, discard it, but you may put it on top of your library instead of into your graveyard.
 id=1122
 name=Library of Leng

projects/mtg/bin/Res/test/_tests.txt

@@ -178,6 +178,7 @@ drift_of_the_dead.txt
 dromad_purebred.txt
 dross_harvester.txt
 duskwalker.txt
+dust_corona.txt
 dwarven_warriors.txt
 ebony_horse.txt
 ekundu_cyclops1_i218.txt
@@ -219,6 +220,8 @@ giant_growth.txt
 giant_growth2.txt
 glimpse_the_unthinkable.txt
 gnarled_effigy.txt
+gnat_alley_creeper1.txt
+gnat_alley_creeper2.txt
 goblin_balloon_brigade.txt
 goblin_balloon_brigade2.txt
 goblin_king.txt
@@ -246,6 +249,7 @@ imaginary_pet.txt
 immaculate_magistrate.txt
 instill_energy_i166.txt
 jodahs_avenger.txt
+juggernaut.txt
 jump.txt
 karns_touch_i233.txt
 keldon_warlord.txt

projects/mtg/bin/Res/test/dust_corona.txt

@@ -0,0 +1,29 @@
+#NAME: Dust Corona
+#DESC: checks an aura which grants
+#DESC: a "can't be blocked by" ability
+[INIT]
+firstmain
+[PLAYER1]
+inplay:Raging Goblin
+hand:Dust Corona
+manapool:{R}
+[PLAYER2]
+inplay:Suntail Hawk
+[DO]
+Dust Corona
+Raging Goblin
+next
+next
+Raging Goblin
+next
+Suntail Hawk
+next
+next
+[ASSERT]
+combatend
+[PLAYER1]
+inplay:Raging Goblin,Dust Corona
+[PLAYER2]
+inplay:Suntail Hawk
+life:17
+[END]

projects/mtg/bin/Res/test/gnat_alley_creeper1.txt

@@ -0,0 +1,23 @@
+#NAME: Gnat Alley Creeper
+#DESC: checks the ability "can't be
+#DESC: blocked by creatures with flying"
+[INIT]
+combatattackers
+[PLAYER1]
+inplay:Gnat Alley Creeper
+[PLAYER2]
+inplay:Suntail Hawk
+[DO]
+Gnat Alley Creeper
+next
+Suntail Hawk
+next
+next
+[ASSERT]
+combatend
+[PLAYER1]
+inplay:Gnat Alley Creeper
+[PLAYER2]
+inplay:Suntail Hawk
+life:17
+[END]

projects/mtg/bin/Res/test/gnat_alley_creeper2.txt

@@ -0,0 +1,23 @@
+#NAME: Gnat Alley Creeper 2
+#DESC: checks the ability "can't be
+#DESC: blocked by creatures with flying"
+#DESC: Pass 2: Does normal blocking work?
+[INIT]
+combatattackers
+[PLAYER1]
+inplay:Gnat Alley Creeper
+[PLAYER2]
+inplay:Raging Goblin
+[DO]
+Gnat Alley Creeper
+next
+Raging Goblin
+next
+next
+[ASSERT]
+combatend
+[PLAYER1]
+graveyard:Gnat Alley Creeper
+[PLAYER2]
+graveyard:Raging Goblin
+[END]

projects/mtg/bin/Res/test/juggernaut.txt

@@ -0,0 +1,23 @@
+#NAME: Juggernaut
+#DESC: checks Juggernaut's ability
+#DESC: "can't be blocked by walls"
+[INIT]
+combatattackers
+[PLAYER1]
+inplay:Juggernaut
+[PLAYER2]
+inplay:Wall of Stone
+[DO]
+Juggernaut
+next
+Wall of Stone
+next
+next
+[ASSERT]
+combatend
+[PLAYER1]
+inplay:Juggernaut
+[PLAYER2]
+inplay:Wall of Stone
+life:15
+[END]

projects/mtg/include/AllAbilities.h

@@ -1190,6 +1190,38 @@ class AProtectionFrom: public MTGAbility{
 };
 
 
+//Can't be blocked by...
+class ACantBeBlockedBy: public MTGAbility{
+ public:
+  TargetChooser * fromTc;
+  ACantBeBlockedBy(int id, MTGCardInstance * _source, MTGCardInstance * _target, TargetChooser *fromTc):MTGAbility(id,_source,_target),fromTc(fromTc){
+
+  }
+
+ int addToGame(){
+   MTGCardInstance * _target = (MTGCardInstance *)target;
+   _target->addCantBeBlockedBy(fromTc);
+   return MTGAbility::addToGame();
+ }
+
+  int destroy(){
+    ((MTGCardInstance *)target)->removeCantBeBlockedBy(fromTc);
+    return 1;
+  }
+
+  ACantBeBlockedBy * clone() const{
+    ACantBeBlockedBy * a =  NEW ACantBeBlockedBy(*this);
+    a->isClone = 1;
+    return a;
+  }
+
+  ~ACantBeBlockedBy(){
+    SAFE_DELETE(fromTc);
+  }
+
+};
+
+
 //Alteration of Power and Toughness  (enchantments)
 class APowerToughnessModifier: public MTGAbility{
  public:

projects/mtg/include/MTGCardInstance.h

@@ -123,6 +123,11 @@ class MTGCardInstance: public CardPrimitive, public MTGCard, public Damageable {
   int removeProtection(TargetChooser *tc, int erase = 0);
   int protectedAgainst(MTGCardInstance * card);
 
+  vector<TargetChooser *>cantBeBlockedBys;
+  int addCantBeBlockedBy(TargetChooser * tc);
+  int removeCantBeBlockedBy(TargetChooser *tc, int erase = 0);
+  int cantBeBlockedBy(MTGCardInstance * card);
+
   void copy(MTGCardInstance * card);
 
   void setUntapping();

projects/mtg/src/MTGAbility.cpp

@@ -737,22 +737,6 @@ MTGAbility * AbilityFactory::parseMagicLine(string s, int id, Spell * spell, MTG
     return a;
   }
 
-  //Gain/loose Ability
-  for (int j = 0; j < Constants::NB_BASIC_ABILITIES; j++){
-    found = s.find(Constants::MTGBasicAbilities[j]);
-    if (found == 0 || found == 1){
-      int modifier = 1;
-      if (found > 0 && s[found-1] == '-') modifier = 0;
-      if (!activated){
-        if(card->hasType("instant") || card->hasType("sorcery")  || forceUEOT){ 
-           return NEW AInstantBasicAbilityModifierUntilEOT(id, card,target, j,modifier);
-        }
-        return NEW ABasicAbilityModifier(id, card,target, j,modifier);
-      }
-      return NEW ABasicAbilityAuraModifierUntilEOT(id, card,target, NULL,j,modifier);
-    }
-  }
-
   //Protection from...
   found = s.find("protection from(");
   if (found == 0){
@@ -771,6 +755,40 @@ MTGAbility * AbilityFactory::parseMagicLine(string s, int id, Spell * spell, MTG
     return NULL; //TODO
   }
 
+  //Can't be blocked by...
+  found = s.find("cantbeblockedby(");
+  if (found == 0){
+    size_t end = s.find (")", found);
+    string targets = s.substr(found+16,end - found - 16);
+    TargetChooserFactory tcf;
+    TargetChooser * fromTc = tcf.createTargetChooser(targets, card);
+    if (!fromTc) return NULL;
+    //default target zone to opponentbattlefield here?
+    if (!activated){
+      if(card->hasType("instant") || card->hasType("sorcery")  || forceUEOT){ 
+         return NULL; //TODO
+      }
+      return NEW ACantBeBlockedBy(id, card,target,fromTc);
+    }
+    return NULL; //TODO
+  }
+
+  //Gain/loose simple Ability
+  for (int j = 0; j < Constants::NB_BASIC_ABILITIES; j++){
+    found = s.find(Constants::MTGBasicAbilities[j]);
+    if (found == 0 || found == 1){
+      int modifier = 1;
+      if (found > 0 && s[found-1] == '-') modifier = 0;
+      if (!activated){
+        if(card->hasType("instant") || card->hasType("sorcery")  || forceUEOT){ 
+           return NEW AInstantBasicAbilityModifierUntilEOT(id, card,target, j,modifier);
+        }
+        return NEW ABasicAbilityModifier(id, card,target, j,modifier);
+      }
+      return NEW ABasicAbilityAuraModifierUntilEOT(id, card,target, NULL,j,modifier);
+    }
+  }
+
   //Untapper (Ley Druid...)
   found = s.find("untap");
   if (found != string::npos){
@@ -845,6 +863,9 @@ int AbilityFactory::abilityEfficiency(MTGAbility * a, Player * p, int mode, Targ
   if (APowerToughnessModifier * abi = dynamic_cast<APowerToughnessModifier *>(a)) return (abi->wppt->power.getValue()>=0 && abi->wppt->toughness.getValue()>=0) ? BAKA_EFFECT_GOOD : BAKA_EFFECT_BAD;
   if (APowerToughnessModifierUntilEndOfTurn * abi = dynamic_cast<APowerToughnessModifierUntilEndOfTurn *>(a)) return abilityEfficiency(abi->ability, p, mode,tc);
 
+  if (dynamic_cast<ACantBeBlockedBy *>(a)) return BAKA_EFFECT_GOOD;
+  if (dynamic_cast<AProtectionFrom *>(a)) return BAKA_EFFECT_GOOD;
+
   map<int,bool> badAbilities;
   badAbilities[Constants::CANTATTACK] = true;
   badAbilities[Constants::CANTBLOCK] = true;

projects/mtg/src/MTGCardInstance.cpp

@@ -353,6 +353,7 @@ int MTGCardInstance::canBlock(MTGCardInstance * opponent){
   if (!opponent->isAttacker()) return 0;
   // Comprehensive rule 502.7f : If a creature with protection attacks, it can't be blocked by creatures that have the stated quality.
   if (opponent->protectedAgainst(this)) return 0;
+  if (opponent->cantBeBlockedBy(this)) return 0;
   if (opponent->basicAbilities[Constants::UNBLOCKABLE]) return 0;
   if (opponent->basicAbilities[Constants::FEAR] && !(hasColor(Constants::MTG_COLOR_ARTIFACT) || hasColor(Constants::MTG_COLOR_BLACK))) return 0;
 
@@ -569,6 +570,33 @@ int MTGCardInstance::protectedAgainst(MTGCardInstance * card){
   return 0;
 }
 
+
+int MTGCardInstance::addCantBeBlockedBy(TargetChooser * tc){
+  cantBeBlockedBys.push_back(tc);
+  return cantBeBlockedBys.size();
+}
+
+int MTGCardInstance::removeCantBeBlockedBy(TargetChooser * tc, int erase){
+  for (size_t i = 0; i < cantBeBlockedBys.size() ; i++){
+    if (cantBeBlockedBys[i] == tc){
+      if (erase) delete (cantBeBlockedBys[i]);
+      cantBeBlockedBys.erase(cantBeBlockedBys.begin()+i);
+      return 1;
+    }
+  }
+  return 0;
+}
+
+int MTGCardInstance::cantBeBlockedBy(MTGCardInstance * card){
+  for (size_t i = 0; i < cantBeBlockedBys.size() ; i++){
+    if (cantBeBlockedBys[i]->canTarget(card)) 
+      return 1;
+  }
+  return 0;
+}
+
+
+
 /* Choose a sound sample to associate to that card */
 JSample * MTGCardInstance::getSample(){
   JSample * js;