Imbalanced features

When making this system, I did my best to balance each feature when used in a normal Attack action. I did not think too much about any major bonuses characters might get from their classes such as rogue's sneak attack, barbarian's brutal critical, or paladin's divine smite. If a character has a feature which synergizes extremely well with a benefit, consider either banning that benefit for that character, or having the benfit cost more.

You could also remove the benefit entirely for all players, but I would rather have a smaller section of players have access to the options than none at all.

Standard 5e balance decisions

While everything should hopefully be balanced using these rules, there are still some design details from standard 5e which you should keep in mind. In general, weapons that are two-handed should do the most damage, simple weapons have no more than 2 or 3 features, and one-handed weapons rarely do more than 1d8 damage. Try to keep to this design unless you have good reason not to.

Custom weapon balance design

In order to curb some of the potential power, here are some suggestions while balancing your weapons.

• You should try to only have 2 or 3 benefits which require much thought. Heavy and two-handed don't require much thought, but area, blunt, ranged, and rapid all will likely require double checking the specific rules. The more traits you have like this, the more you'll forget or get confused.
• Try to keep the damage of a weapon below 2d10 unless you have limited uses of the weapon, with either the limited or recharge benefits, or if you can only attack once with the weapon each turn, such as with loading or slow.
• There are three crit-based benefits: Brutal, increased critical, and killer. Having all three properties makes weapons to slightly more damage than intended, so only take two of the three benefits at a time.

Setting dependance

A lot of the benefits listed are only realistic in a modern or science fiction game. For example, ballistic weapons are usually not found in standard 5e. If you are in a typical fantasy game, ask your DM what types of weapons you might realistically be able to find. You may be able to buy potions that act as grenades, but be unable to buy an equivelant of a flamethrower.

Limited Ammunition

I built this system with each battle in mind. There is no tracking ammunition or total amount of grenades in your backpack. You can buy a set of grenades, and assume that you have enough grenades to use them every turn, or only use them a few times if you have the limited flaw. This is similar to a component pouch, which seems to have an infinite amount of material despite the one-time purchase.

If you want to buy each grenade or similar item individually, then turn the limited flaw into total uses instead of uses per short rest.

The DM has final say

The ultimate rule is that the DM has final say whether or not you can use a weapon, benefit, or flaw. This is a homebrew system that they approved, and they can make changes that they feel are appropriate. Maybe your DM doesn't want any condition or area weapons, or wants crits to be left alone. The DM may also want to be the one to create all the weapons, instead of allowing the players to customize their own.

Booming and green-flame blade

Spells that require you to make an attack roll with a weapon follow all of the rulings of that weapon. If you usually must use an action and bonus action to attack with the weapon, you must use your action and bonus action to use the weapon with the spell.

Optional damage differences

In order to make physical damage types slightly different, you can add this rule:

Bludgeoning, piercing, and slashing each gain a small bonus on critical hits. Bludgeoning allows you to push the target 5 feet away, piercing allows you to reroll a damage die, and slashing allows you to deal damage to another creature within 5 feet of you equal to a damage dice of the weapon.

Fantasy

If you are playing in a standard fantasy world and only want to be able to wield swords, axes, spears, and bows, use these rules:

• Area, condition, damage type, indirect, pointblank, rapid, and saving throw benefits are removed
• Activated, ballistic, recharge, and reload flaws are removed

Simplistic

If you want to stick to the main 5e rules as much as possible, use these rules:

• Only brutal, concealable, finesse, light, nonlethal, powerful, ranged, reach, siege, simple, thrown, and versatile benefits are allowed
• Only heavy, loading, and two-handed flaws are allowed

Bounded Accuracy Fix

If you want to make sure that bounded accuracy doesn't get destroyed, use these rules:

• Accurate, inaccurate, precision, reliable, spray are removed

Pure 5th Edition Feel

If you don't want to play with any mechanic that isn't normally in 5e, use these rules:

• Area, alternate damage, armor piercing, cleave, condition, disarming, free hand, indirect, killer, modular, reliable, secure, silent benefits are removed
• Activated, ballistic, bulky, clumsy, feedback, limited, recharge, reload, set up, slow are removed

Consumables

If you want to have some of your weapons be consumable, use these rules:

• Weapons with the limited flaw must be repurchased to get back uses, instead of recharging after a short rest.

GM Control

If you want this system to only be used by the GM, use these rules:

• Only the GM should look at the weapon creation rules
• The GM can raise or lower the damage die to account for rarity of the item or its cost.

Reasonable Weapons

If you want your weapons to stay near the power of traditional weapons, use these rules:

• The total number of flaws and benefits can not exceed 4.
• The total benefits of a weapon provide no further benefits beyond -3 (2d8 damage).

Rare Magic/Tech

If you want some of the weirder traits to only be allowed on rarer items, use these rules:

• Only the GM is able to make weapons with the following benefits: Area, condition, damage type, free hand, indirect, modular, saving throw, and secure
• Only the GM is able to make weapons with the following flaws: Feedback, limited, recharge

Benefits

Half Benefits

Two-Handed

This weapon requires two hands when you attack with it. This property is relevant only when you attack with the weapon, not when you simply hold it.

Decreased Range

Ranged Weapons only

Decreases the range of a ranged weapon to (40/160). Choosing this twice makes the range (20/80).

Heavy

Creatures that are Small or Tiny have disadvantage on attack rolls with heavy weapons. A heavy weapon's size and bulk make it too large for a Small or Tiny creature to use effectively.

Loading

Because of the time required to load this weapon, you can fire only one piece of ammunition from it when you use an action, bonus action, or reaction to fire it, regardless of the number of attacks you can normally make.

Benefits

Powerful

When you hit with an attack with a powerful weapon, you can choose to push the target 5 ft away from you. The target must not be more than one size larger than you.

You can take this benefit multiple times, pushing the target an additional 5 ft each time.

Precision

Counts as four benefits

Attacks using a precision weapon have advantage.

This benefit costs an additional benefit if the damage dice is 4d4 to 3d8, two additional benefits if the dice is 4d6 to 5d6, three additional benefits if the dice is 4d8 to 7d8, and four additional benefits if the dice is 4d12 or more. Apply this benefit last, except for cleave or rapid.

Rapid

Counts as two benefits

When you take the attack action, you can attack an additional time with the weapon as a bonus action. You don't add your ability modifier to the damage of the bonus attack, unless that modifier is negative.

This benefit costs an additional half benefit for each die above 1d10 (turning a 3d4 into rapid would be three benefits). This benefit also costs two more if you have area or cleave.

Apply this benefit last while calculating the total benefits, after area or cleave (if you have them).

You can make this cost an additional benefit to allow to make an attack with this weapon as a bonus action without needing to use the attack action.

Reliable

Counts as three benefits

When you miss an attack with a reliable weapon, or the target succeeds on the weapon's saving throw, the target takes half of the attacks damage.

This benefit costs an additional benefit if the damage dice is 3d8 to 3d12, and two additional benefits if the dice is 6d6 or more. Apply this benefit last, except for area, cleave or rapid.

Shielding

Counts as two benefits

You gain a +1 AC while wielding this weapon. You only gain this bonus if you are proficient with shields, and the bonus does not stack with a shield.

You can take this benefit an additional time to have a +2 AC bonus.

Stable

Attacks with this weapon deal an additional 1 damage. You can take this benefit multiple times. Apply this benefit last, even after area, cleave, and rapid.

Half Benefits

Slow

Counts as eight flaws

This weapon takes two attacks to use instead of one. If you have the Extra Attack feature, an attack with this weapon uses two of the available attacks. You can also use two attacks on different turns or actions. The actual attack is done on the second attack.

Slow weapons cannot be used in spells or features which have you make one attack as an action, such as booming blade. You cannot make an opportunity attack with a slow weapon unless you've used enough attacks to make the actual attack next.

You can take this flaw multiple times, increasing the amount of attacks it takes to use for each additional time take.

Spray

Counts as six flaws

Attacks using a spray weapon have disadvantage. If you have disadvantage from any other source, the attacks automatically miss.

Tactical

Weapons with the tactical property require 13 Intelligence to be able to use properly. Creatures with less Intelligence have disadvantage on attack rolls using the weapon. You can take this flaw again to require 15 Intelligence.

Half Flaws

Simple Melee Weapons

Simple Ranged Weapons