D&D 5E Breaking the Game with Double Bonus Actions

[dco]

Regardless of its legality or intention, right now there are no big offenders that jump out at me with regards to how balanced turning an action into a bonus action would be.

In almost every case, with two exceptions, I've needed an action or some resource to make that bonus action shine or be desirable. The exceptions would be taking two bonus actions to prepare spells or abilities. Like stacking hex and hexblade hex on one turn. Is even this overpowered? Not really. It is forgoing any offense with the hope that you do not lose concentration and do not get taken down for a large boost to damage the next turn.

The other exception would be to activate multiple bonus action abilities, see magic items or high level monster hunter ranger. The magic item double bonus action could very well get out of hand. The classes taking two bonus actions or even casting two bonus action spells is not a problem. The amount of synergistic combinations, after taking into account the prevalence of concentration, is minimal, still costs spell slots, and is almost always buffing or preparing for the next round.

I say allow it, but let them know that you have the right to rule any particular combination as something you want or not.

*edit: Like, a person could cast mass healing word twice or misty step twice.

If you want to use the bonus action to cast a spell you are limited to one spell and a cantrip, so that problem would not exist.

 

[Uller]

I'd allow it. I look at the reaction and bonus action casting times as minimums...the intention is to allow a caster to cast a spell like healing word and still do something else on their turn not earth shaking...like a cantrip. Magic item bonus actions seem about in that realm.

 

[Lucas Blackstone]

I wouldn't allow it since it isn't legal and it makes you be on the look out for things that were not intended. As an example, multiple bonus actions allows spiritual weapon to be twice as powerful as it is intended to be, which is already pretty good. Far Step is another spell I really like that becomes twice as good if you can take multiple bonus actions. Expeditious Retreat is another one that becomes too good. Normal move 30, dash +30, dash +30 is not intended but would be allowed with multiple bonus actions. None of these are something as overpowered as an unlimited damage combo or anything like that, but clearly too good for they are supposed to be. I'm sure there are more but those are the ones off the top of my head.

Edit: Aura of Vitality doubles its healing ability with double bonus actions also, which is pretty good. I will probably just end up adding all the spells that allow bonus action abilities unless they were really weak and being able to use them twice in a round isn't a real benefit.

 

[jaelis]

As an example, multiple bonus actions allows spiritual weapon to be twice as powerful as it is intended to be, which is already pretty good.

That is true, specifically in levels 3 and 4 a double attack from spiritual weapon will probably do more damage than one attack and a cantrip. But then at level 5 they are back to parity when the cantrip damage goes up. Limiting bonus actions from spells to 1/round is probably safest.

 

[77IM]

You could also say: "Sure, but you can't take the SAME bonus action twice in one round," as that should curb a lot of the most abusive scenarios.

 

[iamntbatman]

Yeah, basically everything that people have come up with that doesn't otherwise break rules (like casting two BA spells would, since you can only cast a cantrip if you cast a BA spell that turn) seems to be based around using the same BA effect twice in one turn, i.e. Misty Step twice, Spiritual Weapon twice (I think the real kicker there is that you'd also be able to move it twice) or similar things. I think I'm going to allow BA's to be used in place of actions as long as no other rules are broken and as long as you don't take the same BA more than once in a turn. I've still yet to see any real gamebreaking scenarios and this seems safest, and also makes sense to me.

 

[Li Shenron]

I just want to add a reminder that most bonus action spells are made so because they are meant to be used in the same turn with an attack.

The extra rule about being able to cast a cantrip in the same turn is because of attack cantrips. Instead of thinking about it as a restriction ("you cannot cast another spell unless it's a cantrip") think of it as an allowance ("you can cast a cantrip").

This reinforces the idea that whatever you do with your bonus action is not "minor" but actually "major". It's the additional attack or cantrip that plays the "minor" part of what you do in the same round.

 

[schnee]

In a session I was DMing, a player wanted to forgo using her action to instead use two bonus actions (one to command a beast from a Bag of Tricks, the other to cast Healing Word). I ruled that this wasn't possible as it's not permitted per RAW, but I immediately caught a lot of flak for the ruling at the table because they all thought it was nuts that you couldn't use a bonus action as an action in lieu of taking an action, especially as the PHB says bonus actions are especially swift.

Too bad for them. The rules are made primarily to play well, and 'common sense' is way down the list.

Go look at yourself in a mirror, and practice these:

"No."
"We stay with the rules as written."
"That's not going to happen."

It gets easier and easier over time.

 

[dco]

Yeah, basically everything that people have come up with that doesn't otherwise break rules (like casting two BA spells would, since you can only cast a cantrip if you cast a BA spell that turn) seems to be based around using the same BA effect twice in one turn, i.e. Misty Step twice, Spiritual Weapon twice (I think the real kicker there is that you'd also be able to move it twice) or similar things. I think I'm going to allow BA's to be used in place of actions as long as no other rules are broken and as long as you don't take the same BA more than once in a turn. I've still yet to see any real gamebreaking scenarios and this seems safest, and also makes sense to me.

RAW spells using a bonus action "must" use the bonus action, for other things is not clear like the bag of tricks. Personally I allow the players to substitute the bonus action for an action but they have to do something else with the bonus action and follow the rest of rules, no cheats of two spiritual weapon attacks in the same turn, you can cast a cantrip and a bonus spell or a spell and a bonus cantrip, if you need to take the attack action you have to take it, etc. For example if the cleric already casted the spiritual weapon and this turn needs to use healing word he can use both and for now it doesn't bring problems to our games.

 

[jodyjohnson]

How long have you been allowing this, and has it ever caused any problems?

I never had a player ask. Currently I DM AL so it isn't an option.