TRPG Combat System Design 101: Variables

                Tabletop RPG combat is a sore spot for many players. Even the most popular system: Dungeons and Dragons can get dull unless you’re a wizard or the dungeon master is exceptionally skilled. In this RPG combat design series, I will be talking about how to design the turn-by-turn combat. This post is about all the variables you can use to add depth to your system.  

                An action is the singe non-movement activity a character does on a player’s turn. This is mostly attacking an enemy, casting a spell, or defending oneself. Let’s take a look at all the variables you can tweak for any given actions.

1.       The Speed of the action in terms of when it resolves in initiative order. Many games represent this by having players roll initiative at the start of combat to determine the order of actions. This makes initiative quick to determine, but detaches it from the actions a player is taking on their turn. Outbreak has players roll speed dice based on each action, so the players must decide between acting quickly and acting more powerfully. This works great in a horror setting, since a player may find out their action is no longer useful when they finally act! However, this requires a round of action declaration where every player says what they are doing and which action they are taking along with a round of action resolution that changes each round. This greatly increases the time it takes to run combat.

2.       The Accuracy of the action in terms of how reliable it is. Virtually every game uses accuracy to some extent. This can be the odds to hit a specific enemy based on a character’s stats, or the odds that a spell or action will be successful in absolute terms (This spell has a 50% of working regardless of enemy). If an action directly affects an opposing character, it’s a good idea to vary the accuracy so there’s a difference between powerful and weak opponents. If the action supports an ally then it’s a good idea to make it automatically successful, so players don’t feel punished for helping each other. Fixed random chance is good for item use, or spell effects mainly cast into the environment (wall spells, controlling the weather, summoning monsters, etc.)

3.       The Potency of the action in terms of how effective it is. The typical representation of this variable is the damage dealt by an attack based on the weapon used. This can be the magnitude of effect of any attempted action though. The amount of healing done by a spell, the distance an enemy is pushed by a charging action, how strong the summoned magical armor is, how far you can detect magic, how hard it is to dispel a magical effect, and anything else you might try!

4.       The cost of the action in terms of how many resources are used to attempt it. Dungeons and Dragons used to use a resource management system only for spellcasting. Casters got a number of spells per day and must use them wisely or they will have to wait until the next day. Now many other classes get actions that can be used only once per encounter, per rest, or per day. Many other RPG systems use a fatigue system where players can gain fatigue to improve the accuracy or potency of an action. Think about using cost to balance weapons of different potency or special attacks that otherwise would always be used (in D&D that could be the fireball spell, the highest damage weapons, the power attack feat, etc.). Giving players a resource to manage makes combat instantly more engaging as players will need to make choices about when and where to use those resources. Cost can also be measured in how many turns it takes before the action occurs although this should be avoided for actions designed to happen in combat. Having to wait 3 turns for an epic killing curse might make sense based on its Potency, but it’s no fun to do nothing for 2 rounds of play.

5.       The range of the action in terms of how far it can affect. Swords can only be used up close, but laser sniper rifles might be able to shoot across a city. Use range to give variety between the actions characters can take with weapons or the spells they can cast. What does a healing action that requires a player to be next to a character look like compared to one that can be shot from a gun? Closely related to range is line of sight, which is where within range the action can affect. Typically, a character can’t use an action on someone hiding in a building or who is otherwise unseen. However, having an action that can attack around corners, shoot in the dark, or cast spells behind a building adds depth.

6.       The breadth of the action in terms of how many targets can be affected. Can a character only attack one opponent with a sword, or can they hit many enemies with a blast of confusion. Think about how many targets an action can affect and whether it should have an area of effect. Spells make a lot of sense to have AOE to represent large magical powers, but don’t be afraid of having weapon attacks affect many enemies if you want a fantast feeling. Closely related to breadth is the rate of fire or rate of attack. How many individual attacks a character gets when they attack multiplies the potency of the attack and gives a faster and more skilled feeling to the character. What if a character has to choose between one single high powered attack and attacking several times with a less potent smaller weapon?

7.       The versatility of the action in terms of how many situations it’s useful in. If your game features underwater storylines, that greatly changes the value of fire and electricity spells. Think about adding highly effective, but situational actions to a player’s available choices along with less effective and more generally useful actions. Also give players the ability to create the circumstances that make their situational actions more effective. A lightning sword that grows more powerful during thunderstorms becomes much more interesting if a player can summon a dangerous storm during battle. Giving players actions that let them change the environment are a great way to add versatility. A spell that creates a cube of wood can be useful as a bridge, a wall, repairing a house, stopping a flood, or anything else the player can imagine. Versatile actions are great for giving players options, but restricted ones can be good too. Just make sure the restrictions aren’t too constricting, are interesting, and can be avoided or worked around. A bow that can only shoot orcs is much less interesting than a bow that is especially potent against orcs.

8.       The Duration of the action in terms of how long its effects last. When considering the duration of an actions’ effects, consider both the impact on the current combat, and the effect after the combat. A spell that makes a wall of fire may deal damage for several rounds of combat, but what if the wall becomes permanent? A permanent wall will have consequences in your world and in roleplaying much more than a temporary one. When considering temporary actions keep in mind that damage dealt now is always more valuable than damage dealt later, so the potency of the action isn’t just divided among the rounds of the effect, it is also reduced. For example if I have an acid blast that deals one damage each turn for 5 turns, if may seem like it will do 5 damage, but what if the enemy is defeated before the duration expires? And the enemy can still attack me before all the damage is dealt! This acid blast will be worth much less than an attack that deals 5 damage all at once. However, the player faces an interesting choice if its between dealing damage now and dealing even greater damage over many turns.

9.       The setup of the action in terms of its impact on actions in the future. A powerful sword attack that weakens my defenses for a round, a spell that makes my allies move faster, or a spell that makes all my enemies easier to hit are all examples of actions with setup. Typically referred to as buffs and debuffs, setup is used in many RPG systems as the effect of spells. Don’t be afraid to add buffs and debuffs to regular actions a player can take. Can I enter a defensive position, spend my hit points to deal more damage, protect an ally, or paralyze a foe with a well-placed strike? Setup is important because it requires players to think about the impact of their actions over many turns and across their whole team to use effectively.

                Taken together, you can tweak each of these variables to create a dynamic combat system. Make sure that each playable class has choices using each of these variables, even sword fighting classes! It’s no fun to just find the best weapon and use the same attack every turn with it over and over! Next time we will use these variables to create a gritty sword and sorcery system so stay tuned!