Combat Tactics
Combat is deadly in The Arena, and combatants routinely perish to the challenges within. When creating a character, and when playing in The Arena, it is good to keep a few key concepts in mind to give your character the best chance of survival. New players may wish to take a look at Simple And Effective Character Builds to get some ideas for easy character builds to maximize your survivability in The Arena.
Action Economy
D&D is structured with an action economy, which is the notion that there is a certain set of actions that a character can take in a given turn, round, or other specified time period. Broadly, every character is able to take an action, interact with an object, and move on his or her turn. Some characters also have options for taking a bonus action. Over the course of a round, a character is also able to take one reaction. This structure is what should guide character creation for anyone who wants their characters to be effective and have a good chance of survival in challenging combat encounters.
In order to take advantage of the D&D turn structure, a character should have one or two good options in any situation to use for an action, a move, a bonus action, and a reaction. Frequently, novice players design characters that "trip over themselves," in the sense that they will expend building resources to develop a character with a huge array of bonus actions, but can then only use one bonus action per turn. Having 10 different bonus action options or building in a way that produces bonus action redundancies (such as multiple ways of getting a bonus dash action) is inefficient when a single, repeatable bonus action is more effective.
At the other end of the spectrum are characters that have no options for bonus actions. If a combat runs for a while, all characters can end up in this boat as they expend resources, but characters should be built with at least a few rounds worth of bonus actions in mind. For instance, when building a spell caster, you should consider at least one or two prepared or known spells being those that can be cast as a bonus action. A bard armed with the healing word spell will, between that spell and Bardic Inspiration, have several turns' worth of bonus actions. Generally, using the Bardic Inspiration early, before any party members have sustained injuries, and then the healing words later, when party members are damaged, is a good use of this mix of options for bonus actions.
Certain classes, such as monks and rogues, have built-in action economy because of class features. When a rogue gets the Cunning Action feature, it has a few options for a bonus action every turn. Likewise, a monk can make use of either a Martial Arts bonus action during an attack, or a Patient Defense or Step of the Wind. Because of features like this, it is unwise to build a rogue or monk in such a way as to pick up a bunch of other options for bonus actions, because they can only ever use one per turn.
Ultimately, you want your character to have the ability to make steady use of bonus actions with minimal investment of building resources in order to attain that. If you have a sorcerer with a lot of known bonus action spells, it is less valuable to take the Quicken Spell option for the Sorcery Points features. But, if your spell list has few to no bonus action spells, it could be a very good idea to make use of the Quicken Spell option. If you play a warlock that makes heavy use of the eldritch blast cantrip, as many warlock builds do, it means it is a good idea to have bonus action spells such as hex or misty step, since a cantrip can be cast in the same turn as a spell with a bonus action casting time; if all of your other spells have casting times of an action, then you will be prohibited from using them in the same turn as your most powerful offensive option.
The other dimension of maximizing bonus action usage is to consider the three axes of offense, defense, and mobility when selecting bonus action options for your character. We can look again to the monk to see this built in: Martial Arts gives an offensive option, Patient Defense gives a defensive option, and Step of the Wind gives a mobility option. The offensive option can be further empowered with Flurry of Blows. This provides a good balance of options for a character, so that they can be ready for whatever The Arena presents. Rogue options are slightly less balanced, with two mobility options in Disengage and Dash when using Cunning Action, and one option, Hide, that is a hybrid of offense and defense. The tradeoff is that monks have to expend resources in the form of ki points to fuel some of the options at their disposal.
Spells and other abilities can be selected with the same three axes in mind. If all your character's spells are geared toward offense, it leaves the character in a tight spot when defense or mobility would serve them better. If all you have is a defensive spell that enhances Armor Class, it is useless when facing foes that only use area of effect abilities. Low-level characters will obviously not be able to maximize options along each axis, but you should have some array of abilities and spells in mind that you can work toward so that your character can continue to be survivable as encounters become more and more difficult, and the opponents your character faces become more multi-faceted and deadly.
In order to take advantage of the D&D turn structure, a character should have one or two good options in any situation to use for an action, a move, a bonus action, and a reaction. Frequently, novice players design characters that "trip over themselves," in the sense that they will expend building resources to develop a character with a huge array of bonus actions, but can then only use one bonus action per turn. Having 10 different bonus action options or building in a way that produces bonus action redundancies (such as multiple ways of getting a bonus dash action) is inefficient when a single, repeatable bonus action is more effective.
At the other end of the spectrum are characters that have no options for bonus actions. If a combat runs for a while, all characters can end up in this boat as they expend resources, but characters should be built with at least a few rounds worth of bonus actions in mind. For instance, when building a spell caster, you should consider at least one or two prepared or known spells being those that can be cast as a bonus action. A bard armed with the healing word spell will, between that spell and Bardic Inspiration, have several turns' worth of bonus actions. Generally, using the Bardic Inspiration early, before any party members have sustained injuries, and then the healing words later, when party members are damaged, is a good use of this mix of options for bonus actions.
Certain classes, such as monks and rogues, have built-in action economy because of class features. When a rogue gets the Cunning Action feature, it has a few options for a bonus action every turn. Likewise, a monk can make use of either a Martial Arts bonus action during an attack, or a Patient Defense or Step of the Wind. Because of features like this, it is unwise to build a rogue or monk in such a way as to pick up a bunch of other options for bonus actions, because they can only ever use one per turn.
Ultimately, you want your character to have the ability to make steady use of bonus actions with minimal investment of building resources in order to attain that. If you have a sorcerer with a lot of known bonus action spells, it is less valuable to take the Quicken Spell option for the Sorcery Points features. But, if your spell list has few to no bonus action spells, it could be a very good idea to make use of the Quicken Spell option. If you play a warlock that makes heavy use of the eldritch blast cantrip, as many warlock builds do, it means it is a good idea to have bonus action spells such as hex or misty step, since a cantrip can be cast in the same turn as a spell with a bonus action casting time; if all of your other spells have casting times of an action, then you will be prohibited from using them in the same turn as your most powerful offensive option.
The other dimension of maximizing bonus action usage is to consider the three axes of offense, defense, and mobility when selecting bonus action options for your character. We can look again to the monk to see this built in: Martial Arts gives an offensive option, Patient Defense gives a defensive option, and Step of the Wind gives a mobility option. The offensive option can be further empowered with Flurry of Blows. This provides a good balance of options for a character, so that they can be ready for whatever The Arena presents. Rogue options are slightly less balanced, with two mobility options in Disengage and Dash when using Cunning Action, and one option, Hide, that is a hybrid of offense and defense. The tradeoff is that monks have to expend resources in the form of ki points to fuel some of the options at their disposal.
Spells and other abilities can be selected with the same three axes in mind. If all your character's spells are geared toward offense, it leaves the character in a tight spot when defense or mobility would serve them better. If all you have is a defensive spell that enhances Armor Class, it is useless when facing foes that only use area of effect abilities. Low-level characters will obviously not be able to maximize options along each axis, but you should have some array of abilities and spells in mind that you can work toward so that your character can continue to be survivable as encounters become more and more difficult, and the opponents your character faces become more multi-faceted and deadly.
Variety and Focus
Both variety and focus are key concepts to keep in mind when designing a character and selecting its various features, spells, and abilities. We know from the discussion of action economy that variety is an element to consider when it comes to figuring out ways to spend actions and bonus actions, because redundancies are not generally valuable, but variety also needs to be considered for both offense and defense when it comes to what your character can do and withstand.
On the offensive front, the most easily-grasped type of variety to consider is spell choice in the context of saving throws. If you are playing a caster and you have built it to have a high spell save DC, then it is a good idea to prepare or select spells that have a variety of different saving throws. If you have a bunch of spells that all rely on STR saving throws, for instance, then your character is going to be quite marginalized in a fight against giants. Likewise, if everything you use relies on INT saving throws, good luck when the mind flayers come calling. You may not be in a position to select a spell for each and every different saving throw, but you can generally break it down into physical or mental and try to select at least one or two spells of each variety. Barring exceptional opponents like dragons, few monsters have great mental and physical saves across the board.
In addition to save variety, you should also consider damage type variety. If all of your spells rely on lightning damage, for instance, you will be in trouble against a storm giant. If you are playing a frontline fighting type, if all of your weapons do slashing damage, you may not be able to maximize your damage output against all types of foes. For that reason, it is good to select a variety of different spell damage types and have a few different damage types in your arsenal of weapons. Your character may prefer to use a battle axe, but it's not a bad idea to have a war hammer as a backup, just in case something is impervious to the slashing damage a battle axe does.
While the concepts of variety and focus may seem at odds, the aforementioned example illustrates that variety allows for focus. Every character will have one or two options in combat that represent their bread-and-butter. If your character is a fighter with the Great Weapon Fighting style, then there is no mystery what your character is about or what it should be trying to do in combat; it should be trying to get up to the enemy and hit it with its two-handed weapon. It does no good, then, for the character to be denied its bread-and-butter option by showing up to a fight with a greatsword and a greataxe against a foe that is immune to slashing damage; it would have been better to have a maul as a backup. Likewise, if your wizard has potent spells that can dish out big damage, then it does no good to show up with five different fire spells against a creature that is immune to fire. In both cases, focus - the character's bread-and-butter ability - hinges on variety; a variety of methods of implementing its most potent combat options means that it will be able to exercise those options more reliably.
This ties back in with the previous mention of the three axes of offense, defense, and mobility. If you are playing a rogue, its signature offensive move is usually to land a sneak attack. By making use of the mobility provided by their Cunning Action, they can get in a position to make a sneak attack. By using the option to hide provided by the Cunning Option, they can potentially gain advantage, thereby getting a sneak attack and making it more likely to hit. Similarly, if you are playing a warlock that has invested a lot into eldritch blast capabilities, it can be quite problematic to get surrounded by enemies up close when you would rather be on the other side of the battlefield. In times like those, a misty step can make all the difference.
Variety is a consideration that enters into every building decision you make for your characters. A character can only concentrate on one spell at a time, so if all of its spells rely on concentration, they will be hamstrung by not being able to cast a new spell without discarding a previous one at the same time, potentially not getting the most out of it. If all your defense is allotted toward Armor Class or one particular saving throw, as soon as an enemy comes along that uses an attack that targets your weakness, it could spell disaster. If you have 10 different options for a reaction that all trigger off of the same event, but no options that trigger off the many other types of events that can occur, you're out of luck in any situation where your specific trigger cannot happen. If all your reactions are offensive but a defensive reaction is all you would need to last another round to make another attack, and you only need to do one more point of damage to prevent a TPK, you will wish you had selected at least one defensive option.
On the offensive front, the most easily-grasped type of variety to consider is spell choice in the context of saving throws. If you are playing a caster and you have built it to have a high spell save DC, then it is a good idea to prepare or select spells that have a variety of different saving throws. If you have a bunch of spells that all rely on STR saving throws, for instance, then your character is going to be quite marginalized in a fight against giants. Likewise, if everything you use relies on INT saving throws, good luck when the mind flayers come calling. You may not be in a position to select a spell for each and every different saving throw, but you can generally break it down into physical or mental and try to select at least one or two spells of each variety. Barring exceptional opponents like dragons, few monsters have great mental and physical saves across the board.
In addition to save variety, you should also consider damage type variety. If all of your spells rely on lightning damage, for instance, you will be in trouble against a storm giant. If you are playing a frontline fighting type, if all of your weapons do slashing damage, you may not be able to maximize your damage output against all types of foes. For that reason, it is good to select a variety of different spell damage types and have a few different damage types in your arsenal of weapons. Your character may prefer to use a battle axe, but it's not a bad idea to have a war hammer as a backup, just in case something is impervious to the slashing damage a battle axe does.
While the concepts of variety and focus may seem at odds, the aforementioned example illustrates that variety allows for focus. Every character will have one or two options in combat that represent their bread-and-butter. If your character is a fighter with the Great Weapon Fighting style, then there is no mystery what your character is about or what it should be trying to do in combat; it should be trying to get up to the enemy and hit it with its two-handed weapon. It does no good, then, for the character to be denied its bread-and-butter option by showing up to a fight with a greatsword and a greataxe against a foe that is immune to slashing damage; it would have been better to have a maul as a backup. Likewise, if your wizard has potent spells that can dish out big damage, then it does no good to show up with five different fire spells against a creature that is immune to fire. In both cases, focus - the character's bread-and-butter ability - hinges on variety; a variety of methods of implementing its most potent combat options means that it will be able to exercise those options more reliably.
This ties back in with the previous mention of the three axes of offense, defense, and mobility. If you are playing a rogue, its signature offensive move is usually to land a sneak attack. By making use of the mobility provided by their Cunning Action, they can get in a position to make a sneak attack. By using the option to hide provided by the Cunning Option, they can potentially gain advantage, thereby getting a sneak attack and making it more likely to hit. Similarly, if you are playing a warlock that has invested a lot into eldritch blast capabilities, it can be quite problematic to get surrounded by enemies up close when you would rather be on the other side of the battlefield. In times like those, a misty step can make all the difference.
Variety is a consideration that enters into every building decision you make for your characters. A character can only concentrate on one spell at a time, so if all of its spells rely on concentration, they will be hamstrung by not being able to cast a new spell without discarding a previous one at the same time, potentially not getting the most out of it. If all your defense is allotted toward Armor Class or one particular saving throw, as soon as an enemy comes along that uses an attack that targets your weakness, it could spell disaster. If you have 10 different options for a reaction that all trigger off of the same event, but no options that trigger off the many other types of events that can occur, you're out of luck in any situation where your specific trigger cannot happen. If all your reactions are offensive but a defensive reaction is all you would need to last another round to make another attack, and you only need to do one more point of damage to prevent a TPK, you will wish you had selected at least one defensive option.