Opportunity attacks in 5e, in my humble opinion, make combat boring. Disengaging to avoid an Attack of Opportunity (AoO) sacrifices your own action but leaves the enemy’s in-tact, making it one of the worst trades in the game. While the mechanic can create tense situations, it often does so at the expense of fun, and it certainly at the expense of allowing combat in 5e to be tactical. When standing still is the optimal move, players and monsters are very likely to do so.
Attacks of Opportunity should be unexpected ways in which someone’s turn is interrupted to help simulate the chaos of battle in the turn-based, orderly system (Shout out to my friend Ronin for helping me find the words to express this.)
Simply turning off the Attack of Opportunity rules doesn’t quite fix the problem. Tactics become more important and players become more curious about moving through opponents and opponents moving through them, but the chaos of battle is conspicuously missing. Here are two ways to solve that, one of them complicated, the other not.
METHOD ONE – SIMPLE OPPORTUNITY ATTACK RULES
Anyone wielding a martial weapon they are proficient in can make an opportunity attack against a creature that misses them with a weapon attack. Doing so costs one reaction. Monks can make this opportunity attack regardless of the weapon (or lack thereof) that they’re wielding.
Only the Sentinel feat allows for making an Attack of Opportunity when a creature leaves your space.
The Disengage action works exactly the same as RAW, but now only Goblins and Rogues benefit from it in a clear way (Bonus action to disengage, action to attack without fear of reprisal.)
Simple. Clean. Done. Enjoy a much more mobile combat.
Monsters are almost always proficient with their weapons, so DMs only need to worry about creatures with Martial weapons. Easy goblins use daggers. Terrifying goblins use short-swords.
Hobgoblins have probably taken over the world with this rule change. They are made out of AC and their attacks hit like Buicks, as we’ve discussed.
METHOD TWO – MODULAR OPPORTUNITY ATTACK RULES
These rules are for groups that prefer modularity to their game.
The RAW Attack of Opportunity described in the PHB is turned off in this rule set, and by default, no one can make any Attack of Opportunity at a moving creature. Exceptions are outlined below.
LEARNING AN ATTACK OF OPPORTUNITY
Opportunity attacks come from formal combat training. In the simple rules, we represent that by tying AoOs to martial weapon proficiency. In the crunchy rules, we’re going to do it by attaching most of them to Fighting Styles.
FIGHTING STYLE ATTACKS OF OPPORTUNITY
+2 to attack rolls with ranged weapons.
AoO: The Whites of Their EyesIf you are holding a ranged weapon, you can use your reaction to make a Ranged Weapon Attack when a creature passes from your weapon’s long range into its close range (the number on the left of your ranged weapon’s range value, which says something like 30/60).
Some notes for this: it is specifically for when creatures charge. A creature that passes from a weapon’s long range into its short range is subject to the AoO. A creature that begins its turn in the close range isn’t an eligible target, nor is a creature that teleported or into range.
Blessed Warrior / Druidic Warrior
You learn two cantrips of your choice from the cleric / druid spell list. They count as paladin / ranger spells for you, and Charisma / Wisdom is your spellcasting ability for them. Whenever you gain a level in this class, you can replace one of these cantrips with another cantrip from the cleric / druid spell list.
AoO: So Anyway, I started BlastingYou can use your reaction to cast a Cantrip at an enemy or an Ally when they first enter the range of that cantrip.
Like with the AoO for Archery, this works when a creature passes from out of range to in-range. It does mean that you can cast cantrips like Resistance on passing allies, and that you can switch cantrips around. For example, a creature approaching you steps into range of Chill Touch – and then next round, steps into range of Green Flame Blade.
You have blindsight with a range of 10 feet. Within that range, you can effectively see anything that isn’t behind total cover, even if you’re blinded or in darkness. Moreover, you can see an invisible creature within that range, unless the creature successfully hides from you.
AoO: VersatilityYou can choose the Whirlwind, Counter-Attack, or Seize an Opening Attack of Opportunity as a part of the training that gave you your Blind Fighting.
While you are wearing armor, you gain a +1 bonus to AC.
AoO: Counter-AttackWhen a creature misses you with an attack, you can use your reaction to make an attack against that creature.
When you are wielding a melee weapon in one hand and no other weapons, you gain a +2 bonus to damage rolls with that weapon.
AoO: Challenge AcceptedAs a bonus action, you can begin a duel with a creature. You can only duel one creature at a time. A duel ends when you or the creature fall to 0 hit-points.
You can use a reaction to make an attack of opportunity against a creature you’re dueling during its turn.
Great Weapon Fighting
When you roll a 1 or 2 on a damage die for an Attack you make with a melee weapon that you are wielding with two hands, you can reroll the die and must use the new roll, even if the new roll is a 1 or a 2. The weapon must have the Two-Handed or Versatile property for you to gain this benefit.
AoO: Seize an OpeningWhen an enemy is forced to make a saving throw while within melee range of you, you can use your reaction to seize the opportunity and make a melee weapon attack.
When you damage a creature with a melee weapon attack, you can Harry them with a bonus action. Harried creatures attack everyone except you at disadvantage. Only one creature can be Harried at a time, and it stops being Harried at the beginning of your next turn or until you move away from it.
AoO: InterferenceIf an ally would take damage that knocks them unconscious, you can use your reaction to move up to your speed to a space within 5 feet of them and within melee-attack-range of the attacker. If you reach this space, you take this damage instead, and can make a weapon attack against the attacker.
You cannot prevent an ally from taking this damage if you were also affected by the damage before moving.
When you engage in two-weapon fighting, you can add your ability modifier to the damage of the second attack.
AoO: WhirlwindWhen a creature enters your reach, you can use a reaction to make a weapon attack against them. If the attack lands, you roll the damage for both of your weapons.
CLASS ATTACKS OF OPPORTUNITY
AoO: STOP THAT!When a creature within range of your unarmed attacks deals damage to you while you’re raging, you can use your reaction to make a grapple or shove attack against them.
AoO: Stolen MomentumWhen a creature attacks you with a melee weapon attack, you can use a reaction to make an athletics or acrobatics check against their attack roll. On a success, you take half damage and they take your Strength or Dexterity modifier plus your Level as damage. You additionally gain a Ki point if you are missing any.
AoO: CalculationWhen an opponent with a lower initiative score than you begins their turn, on the first round of combat you can use your reaction to make a weapon attack against them.
Invocation: Shadow BladeRequires: Pact of the BladeThe shadow of your pact weapon is as real and solid as any steel and you can command it to lash out at nearby enemies. When an opponent ends their turn within your reach, or within twice your reach if you are in dim light or darkness, you can use your reaction to force them to make a constitution saving throw versus your Warlock spell save DC. If they fail, they take your weapon damage + cha mod force damage.
Block Action (New)
You can use a reaction to try to block creatures from going around you (but not away from you). The space within your reach (for example, 10 feet if you’re equipped with a pole-arm) becomes difficult terrain until the start of your next turn. If you block a creature, it has three choices:
It ceases all movement for the turn, but retains any remaining actions.It can take a Dodge Action and try to move past you. It rolls acrobatics against your weapon attack. On a failure, it takes weapon damage. If it takes weapon damage, it also stops moving, as if per the Sentinel Feat. This counts as an attack of opportunity.It can try to Overrun you. This provokes a special Attack of Opportunity where you roll a melee weapon attack (instead of Athletics) against the creature’s Athletics. If you succeed, the creature takes damage and its speed falls to 0 for the rest of the round. If you fail, the creature can finish its movement, and it is larger than you, you are also knocked prone.
Removed. Changes to the Dodge Action mean Rogues can still try to do hit-and-run tactics against block.
As always, you can Dodge as an action and attacks made against you are made at disadvantage until the beginning of your next turn. You can additionally move past creatures that are Blocking you (assuming you can move around them) as if the space within their reach was difficult terrain.
You can Dodge as a reaction when you take damage other than radiant, necrotic, force, or psychic damage from a weapon or spell attack (IE, if the caster rolled to hit you.) Subtract your Acrobatics (Dex) score from the damage of the attack if your Acrobatics check is higher than the attack roll. [[This is added to try to add some competition to AoO’s for the use of a reaction, as well as to give characters that may not have a reaction something to use it on.]]
Changes to existing feats are in bold.
When you hit a creature with an opportunity attack, the creature’s speed becomes 0 for the rest of the turn.You gain the Attack of Opportunity from a fighting style, even if you do not have that or any other fighting style. (Casters can take Holy or Druidic Warrior’s attack of opportunity and apply it to their own cantrips.)When a creature within 5 feet of you makes an attack against a target other than you (and that target doesn’t have this feat), you can use your reaction to make a melee weapon attack against the attacking creature.
You can use your reaction to cast a Spell at an enemy or an Ally when they first enter the range of that Spell. The spell must have a casting time of 1 action and must target only that creature.You have advantage on Constitution saving throws that you make to maintain your concentration on a spell when you take damage.You can perform the somatic components of spells even when you have weapons or a shield in one or both hands.