add a jam modifier

megamek/src/megamek/common/MekView.java

@@ -635,6 +635,8 @@ private String modifierText(EquipmentModifier modifier) {
             return damageModifier.formattedDamageModifier() + " damage";
         } else if (modifier instanceof WeaponMisfireModifier) {
             return "weapon may misfire";
+        } else if (modifier instanceof WeaponJamModifier) {
+            return "weapon may jam";
         } else {
             return "unknown";
         }

megamek/src/megamek/common/modifiers/SalvagQualityWeaponJamModifier.java

@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2024 - The MegaMek Team. All Rights Reserved.
+ *
+ * This file is part of MegaMek.
+ *
+ * MegaMek is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * MegaMek is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with MegaMek. If not, see <http://www.gnu.org/licenses/>.
+ */
+package megamek.common.modifiers;
+
+/**
+ * This class represents a modifier that is one of the options for weapons at salvage quality, CO p.215. It makes the weapon jam on a to hit
+ * roll of 2 or 3 and is applicable for missile and ballistic weapons.
+ */
+public class SalvagQualityWeaponJamModifier extends WeaponJamModifier {
+
+    /**
+     * Creates a weapon jam modifier for salvage quality missile and ballistic weapons, CO p.215. It makes the weapon jam on a to hit roll
+     * of 2 or 3.
+     */
+    public SalvagQualityWeaponJamModifier() {
+        super(Reason.SALVAGE_QUALITY, 2, 3);
+    }
+}

megamek/src/megamek/common/modifiers/WeaponHeatModifier.java

@@ -19,8 +19,7 @@
 package megamek.common.modifiers;
 
 /**
- * This is an EquipmentModifier that changes the heat generation of a weapon (WeaponMounted). This can be a simple addition or subtraction,
- * but also a more complicated method.
+ * This is an EquipmentModifier that changes the heat generation of a weapon (WeaponMounted).
  *
  * Note that multiple such heat modifiers can be applied to a weapon. Their effects stack by being applied one after the other.
  */

megamek/src/megamek/common/modifiers/WeaponJamModifier.java

@@ -0,0 +1,78 @@
+/*
+ * Copyright (c) 2024 - The MegaMek Team. All Rights Reserved.
+ *
+ * This file is part of MegaMek.
+ *
+ * MegaMek is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * MegaMek is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with MegaMek. If not, see <http://www.gnu.org/licenses/>.
+ */
+package megamek.common.modifiers;
+
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.HashSet;
+import java.util.Set;
+import java.util.function.Predicate;
+
+/**
+ * This is an EquipmentModifier that jams a weapon (WeaponMounted) upon certain to hit roll results. Note that the modifier can be applied
+ * to any weapon, even energy weapons. Also, multiple such modifiers can be applied to a weapon; each of those is checked and the weapon
+ * is jammed if any modifier's roll results happen.
+ */
+public class WeaponJamModifier extends AbstractEquipmentModifier {
+
+    private final Set<Integer> jamRollResults = new HashSet<>();
+
+    /**
+     * Creates a weapon modifier that makes the weapon jam if the die roll matches a given test.
+     *
+     * A modifier that makes the weapon jam on to hit rolls of 7 or more can be created like this:
+     * <pre>{@code
+     * new WeaponJamModifier(roll -> roll >= 7);
+     * }</pre>
+     *
+     * @param misfireTest The test of the die roll result that returns true when a jam occurs
+     */
+    public WeaponJamModifier(Predicate<Integer> misfireTest, Reason reason) {
+        super(reason);
+        for (int i = 2; i <= 12; i++) {
+            if (misfireTest.test(i)) {
+                jamRollResults.add(i);
+            }
+        }
+    }
+
+    /**
+     * Creates a weapon modifier that makes the weapon jam if the die roll matches any of the given numbers.
+     *
+     * @param jamRollResults A list of numbers (2...12) that make the weapon jam when rolled as a to-hit roll.
+     */
+    public WeaponJamModifier(Reason reason, int... jamRollResults) {
+        super(reason);
+        Arrays.stream(jamRollResults).forEach(this.jamRollResults::add);
+    }
+
+    /**
+     * Creates a weapon modifier that makes the weapon jam if the die roll matches any of the given numbers.
+     *
+     * @param jamRollResults A list of numbers (2...12) that make the weapon jam when rolled as a to-hit roll.
+     */
+    public WeaponJamModifier(Collection<Integer> jamRollResults, Reason reason) {
+        super(reason);
+        this.jamRollResults.addAll(jamRollResults);
+    }
+
+    public boolean isJammed(int toHitRollResult) {
+        return jamRollResults.contains(toHitRollResult);
+    }
+}