A neat way to encourage teamwork and partnership midcombat: get a bonus when you combine your action with another character! You’ve probably seen things like it before in comics and action movies. The “fastball special” when Colossus throws Wolverine at an enemy. Hawkeye firing an arrow with Ant-Man hiding microscopically on the arrowhead. The ol’ one-two.
The mechanic I’m using for this is to let players use a teamup attack whenever two players roll the same intiative result, but you could feasibly let them do it if they ready their actions appropriately and make proper rolls for whatever they are trying to do. But otherwise, you just add some sort of condition or bonus damage to the attack, along with the regular damage from both players’ attacks. It’s that easy! After the first teamup attack, the players resolve initiative normally by figuring out which player has the higher modifier or rerolling.
The fun part of this mechanic is you or your players coming up with a special attack! Check out some examples I came up with below.
Half-Orc Barbarian + Halfling Rogue: The Barbarian uses their strength to throw the rogue at an unwary enemy! The attack deals the regular sneak attack damage plus the barbarian’s regular attack damage, and then knocks the target prone.
Fighter + Druid: The Druid casts Entangle or Thorn Whip or some such spell to wrap up the target’s feet, setting up the Fighter (or any martial class, really) to knock them down with a heavy blow to the torso or head. This deals the Druid’s normal damage from the spell (if applicable) and then the Fighter’s damage, plus knocks the target prone.
Way of Shadow Monk + Assassin Rogue: Alternating attacks from each player jumping out of hiding and back into the shadows between each strike confuses the enemy. The target has disadvantage on all attacks during its next turn and cannot move more than 5 feet. It also takes the Monk’s and Rogue’s regular attack damage.
Nail on the Head
Great Weapon Paladin + Archery Ranger: The Ranger hits the creature with an arrow, and then the Paladin follows through with their two-handed maul, hammering the arrow deeper into the creature’s wound. This deals regular damage from the Paladin and Ranger plus causes the creature to bleed for 1d4 damage each round for three rounds.
Come to Deity
Paladin + Cleric: One of the players sweeps the target’s feet and the other whacks the back of their head, causing the target to fall into a kneeling position before the two holy heroes. The damage from both players coupled with their righteous auras causes the creature to become Frightened for one round.
Who Turned Out the Lights?
Fighter + Rogue: The Rogue pulls some of the target’s clothing or a bag over the target’s head, blinding them for 1 round if they are subject to such a condition. The Fighter and Rogue then wail on the creature with their attacks, each of which is made at advantage.
Good Cleric + Fiend Warlock: The two players blast the target with spells of both fiendish and celestial energy, like an Eldritch Blast and Sacred Flame. The diametric energies surge through the target and vibrate enough to damage their very soul. The creature gains 1d2 levels of Exhaustion in addition to regular damage.
Sorcerer + Wizard: The two spellcasters cast spells with different energy types simultaneously. The target(s) are Stunned for one round from their bodies trying to recover from the shock to their system. The creature or creatures take regular damage from the spells.
Bard + Sorcerer: The Bard guides the energy of the Sorcerer’s spell with their musical magic, fascinating everyone who can see the spell (but not the initial targets of the spell). These creatures gain disadvantage on Perception checks and have their attention drawn to the spell’s effect, even if they were in the middle of combat, giving their enemies a chance to make Stealth checks. The Bard adds a die equal to their Bardic Inspiration die to the Sorcerer’s spell damage, without expending a use of Bardic Inspiration.
Wizard + Wizard of different school: The two Wizards combine the culmination of their studies to reach a magical revelation of sorts. They can each combine a spell from their chosen schools of magic to create a new spell, limited only by the imagination of the two players. For example, a Shocking Grasp and Phantom Steed launches an electrified steed at the target, becoming a regular Phantom Steed after the damage is dealt. The spell combines the damage of both base spells plus 2d6 damage, if either of the spells deal damage.
Rain of Arrows/Torrent of Blows
Ranger + Ranger: The two Rangers barrage the target with either their dual weapons or multiple arrows. The creature hesitates offering each ranger time for an additional attack in addition to their regular attacks, each at -1.
Look Behind You
Archery Ranger + Rogue: The Ranger and Rogue attack from hiding and use each other’s attacks to distract the creature from one another. The attacks deal a bonus 1d4 damage and do not reveal either player’s hiding place.
Bard + Druid: The Bard’s music combines with the Druid’s natural affinity to call a woodland creature to aid in the battle. This round, the Bard and Druid both deal damage from their respective spells or attacks. Next round, between the Druid and Bard’s initiative, a beast of CR 2 or less arrives to make an attack against a target the Bard and Druid agree upon, using the higher of the two characters’ proficiency modifiers to the attack and damage rolls. The beast then retreats back into the wilderness.
Warlock + Barbarian: The Warlock infuses the Barbarian’s open mind with the force of their patron to fuel their rage. The Warlock can use its action each round to maintain this bond. While infused, the Barbarian’s last attack each round deals damage equal to the Warlock’s Eldritch Blast damage plus 1d10 additional damage.
Cleric + Draconic Bloodline Sorcerer: Through the Cleric’s exaltation to the draconic deities and the Sorcerer’s draconic origin, the two of you call a dragon to your aid. The Cleric and Sorcerer deal no damage this round. Next round, however, a Young dragon of the Cleric’s or Sorcerer’s choice arrives to use its breath weapon on a 15′ radius area they agree upon, using the dragon’s regular damage and saving throw. The dragon then leaves once its air raid is complete. (this one is a bit of a stretch, but I think that it’s fair if they forego their damage for a round to gain about 16d6 (possibly halved) damage on a small area.)
edit: It was also brought to my attention that Pathfinder’s Teamwork feats are a great example for these! Two I liked were Cover Fire and Harder They Fall. The former lets you use your ranged attacks to also use the Aid action, which i think still works in 5e. The latter lets you help an ally make a bull rush (Shove in 5e) attempt against a creature two sizes bigger than normal, which sounds like something that can be adapted! Even if you don’t use an explicit mechanic, always remember to think outside the box during he game and use teamwork to your advantage!