Avoiding PCs Using the Same Action Every Round

For me, a good combat in D&D 5E involves players engaged, thinking, strategizing, and playing off of each other. Every player hangs on seeing what the other players are doing. The action is intense and varied. PCs work together. Players aren't just waiting on their turn. Not every combat has to be this way, but there are times when I want this level of combat.

For me, as a GM, one thing that breaks this type of combat is a PC simply taking the same exact action over and over. They are on cruise control. They aren't surprising the other players with their actions. They aren't working together as part of the team. Now, I have played with awesome players and I can tell you this isn't a player problem. Some classes do one thing well in combat and they use it. That is the way the class plays out based on its designed. As a GM, I want to help solve this issue in my games. I want players to have options.

The first solution that fixes most of the problems is putting together interesting combat. Add some terrain. Add weather effects. Add cover. Mix melee, ranged, and caster foes. Use tactics. Have the battlefield change over the course of the battle. Have foes and/or allies arrive and flee the battle. Use foes that play off of each other, use combinations of abilities, and use tactics.

To make it more effect I add all of the extra actions from the DMG. I also rule the RAW so more interesting things can happen: if you can grapple an opponent and lift them, you can wield them as an improvised weapon. They and your target both take the damage. A PC strong enough to grapple two foes can even smash them together as improvised weapon damage. I encourage players to shove foes off of cliffs, take cover, and use tactics to have fun.

One PC type that was problematic for a while was the ranged attacked with a bow / crossbow / sling. I make X attacks with my weapon, sometimes with special abilities, and it repeats round after round. To fix this problem, I put together some interesting ammunition:

Type	Description	Rarity	Modifiers
Whistling Arrow / Bolt		Common	Deals no damage
Flask Arrow / Bolt	Ammunition contains a flask that breaks on a hit. Common liquids that are placed in the flask can include water (for dousing flames), oil (make a target slippery or flammable), acid (acid damage).	Common	Range is Halved
Streaking Arrow	When fired into the air, it leaves behind a visible trail that can be seen for miles	Common	Deals no damage
Caltrop Arrow / Bolt	On a hit, the caltrops contained within are dispersed per the normal rules for caltrops.	Uncommon	Deals no damage
Grappling Arrow / Bolt	On a hit, the ammunition deploys a grappling hook attached to a 50ft rope of spider silk.	Uncommon	Disadvantage
Lantern Arrow / Bolt	On a hit, the ammunition ignites, providing light equivalent to a torch for 1min.	Uncommon	Deals no damage
Blunt Arrow / Bolt	Deals bludgeoning damage, optionally nonlethal	Uncommon	None
Arrow / Bolt of Entanglement	On a hit the target becomes prone and restrained until it uses an action to free iteself	Uncommon	Deals no damage
Immovable Arrow / Bolt	On a hit the ammunition becomes immovable until a specific word is spoken. Refer to immovable rod for details.	Uncommon	None

Type	Description	Rarity	Modifiers
Arrow / Bolt of Healing	On a hit, the ammunition deals normal damage and then heals for 3d10.	Rare	The target can try to be struck, giving the attacker advantage.
Arrow / Bolt of Dispelling	On a hit, it behaves as Dispel Magic	Rare	None
Arrow / Bolt of Faerie Fire	On a hit, the target is targeted by the spell Faerie Fire	Rare	None
Arrow / Bolt of Lockpicking	On a hit, the ammunition destroys a single lock	Rare	Disadvantage
Bang Arrow / Bolt	On a hit, the ammunition deals an addition 1d10 thunder damage in a loud boom that can be heard for 300 ft	Rare	None
Arrow / Bolt of Dominate	On a hit, the target is subject to the spell Dominate Person	Rare	None
Arrow / Bolt of Silence	On a hit, the spell Silence is cast on the target or location	Rare	None
Blinkback Arrow / Bolt	On a hit, the target must make a DC 18 Wisdom save or be immediately teleported adjacent to the attacker	Rare	None
Arrow / Bolt of Tracking	Once fired, the attacker knows the distance and bearing to the ammunition at all times until the effect is dispelled with a specific word	Very Rare	None
Antimagic Arrow	On a hit, the ammunition generates an antimagic field with 30 ft radius. Within this radius, spells automatically fail, spell effects cannot manifest, and summoned creatures are unsummoned. The effect lasts for 1 minute.	Very Rare	None
Blink Arrow / Bolt	The arrow can blink in and out of the material plane (into the ethereal plane) along its path to bypass solid objects such as walls. The attacker must be able to discern the location of the target. The GM may add additional conditions to hit it the target is not visible to the attacker.	Very Rare	None
Ethereal Arrow / Bolt	The ammunition travels through the ethereal plane and can only hit targets that reside in the ethereal plane.		None

Type	Description	Rarity	Modifiers
Arrow / Bolt of Rift	On a hit, a rift is opened to another random plane and all objects and creatures within 10ft of the rift are sucked through. The rift then immediately closes.	Legendary	None
Arrow / Bolt of Slaying	The target must make a DC 24 Constitution save or it is immediately dropped to hero hit points. On a successful save, its hit points are reduced by half its maximum hit points.	Legendary	None
Temporal Arrow / Bolt	As a free action, the possessor of the ammunition can choose to have it hit any target as a critical hit. The arrow must be fired by the possessor at that location in the future, or a temporal paradox will manifest causing the possessor to be completely erased from all timelines.	Legendary	None

I put these arrows into play and more interesting things start to happen. So far, I've just scratched the surface with them in my game, and I will be bumping up their use in my games ahead.

So that leaves another specific class that I've seen time and time again use one action over and over in combat: the warlock and eldritch blast.

Warlock gets the best cantrip in the game with eldritch blast. Throw agonizing blast on top of it and you mostly can't beat it. The warlock gets very few spell slots, and although they recharge on a short rest, they are too few and too valuable to use all the time in combat. The warlock usually falls back on eldritch blast.

I posed the question out to the twitter community as to what they do in their games to encourage other actions besides the typical warlock spamming of eldritch blast.  The results were not good (refer to this post). After digging through the results, I was able to pull out some of the gems. Here's the summarized list:

• Allowing the warlock to request new options from their patron.
• Allow eldritch blasts to build a sorcery point like pool of corruption that can be spent to do other things.
• Give them magic items, especially something that gives more spell slots / store spells.
• Buff the warlock, giving them a faster spell progression.
• Add invocations to scale their familiar to make them more useful in combat at higher levels.
• Expand Eldritch Blast into multiple versions that do extra / other things.
• Add invocations for Eldritch Blast to allow grapple, disarm, shoves.
• Let the warlock use a different spell list.
• Add an escalating chance of failure with repeated use eldritch blast.

Magic items are obviously a great way to add options. However, there is no real guarantee who in the party will get them. With warlock, it is difficult to specialize a weapon just for them.

I considered looking at a warlock rewrite, but I'd prefer not to jump too far away from RAW warlock. Building too much homebrew in throws players and the game off and turns a lot of players away. Besides, warlock is awesome for roleplay and in non-combat encounters and I don't want to lose that.

Ultimately, here is the solution I came up with, inspired by a couple of the comments: 

For spells that use an attack roll and do force damage, a caster can choose, before an attack roll is made, to instead do one of the following in lieu of the normal force damage:

• Disarm the target, using the normal spell attack roll
• Shove the target (either 5 ft or prone) using the attack roll in place of the normal Strength(Athletics) check
• Perform the help action to grant advantage on an ally's next attack vs the same target before the start of your next turn

The choice to take one of the above actions may be done independently for each attack granted by the spell.

The following spells would be affected by this houserule:

• Arcane / Bigby's Hand (Clenched Fist)
• Chaos Bolt
• Eldritch Blast
• Mordekainen's Sword
• Spiritual Weapon
• Steel Wind Strike

I proposed this as a change to my 5E game that has warlock in play and another soon to be in play. The rule was generally liked and the very next combat, it was in use and useful. It broke up the combat. I don't think it will always be used in every combat, but it worked well so far.