One of the more fascinating mechanics of the 5th edition of Dungeons & Dragons is the concentration mechanic. For those not familiar with the mechanic, it creates a limitation on how many spell effects can be used at once. Each caster may only concentrate on one spell with a duration of concentration; thus, there is no way that a caster could maintain both a fly spell and a haste spell at the same time. A character could have both spells affecting them at once, but it would require the services of two casters to do so.
The reason that the mechanic exists is primarily a reaction to 3rd Edition D&D. In that edition, it was possible to layer effect on effect until a fully buffed character could have six or more enhancement spells working on them at once, and was very unbalanced in combat. Keeping track of the modifiers was a nightmare, especially when a dispel magic stripped away some effects and left others! Likewise, magic items stacked as well – this led to the attunement mechanic in 5E.
3E did attempt to balance this by naming all the modifiers and saying modifiers with the same name didn’t stack. So, if you had a +2 morale bonus to hit and a +1 morale bonus to hit, you only had a +2 bonus, not a +3. Unfortunately, foolish designers kept adding new names, and the bonuses got too high.
So, Concentration. Two main types of spells use the mechanic:
- Spells that give a significant ongoing bonus to an ally
- Spells that give a significant ongoing penalty to an opponent
The latter includes such spells as hold person. Taking a character out of the fight is tremendously powerful; making it a concentration duration lowers its impact. Some of these spells may be a bit too conservatively balanced, but any player who has been hit by a hold person spell knows how frustrating it is to be unable to act during an extended combat sequence!
I would say that knowing how concentration works is one of the key features of playing an effective spellcaster in 5E. Getting it wrong can cause a lot of problems. If your lose concentration on a spell, the spell ends. What can break concentration?
- Casting another spell that requires concentration
- Taking damage (you get a Constitution saving throw to avoid losing concentration)
- Being incapacitated or killed
Becoming incapacitated doesn’t just mean being knocked unconscious. Paralysation also causes incapacitation; a hold person spell or a ghoul can swiftly end your ability to concentrate on spells.
Incapacitation can have particularly humorous effects (at least for the DM) when it happens. In a recent game of Curse of Strahd, a wizard cast a fly spell on a fighter, so he could go and scout a tower. The fighter found something – a Vrock! The Vrock ignored the fighter, flew down to the rest of the party and let loose its stunning screech attack. The wizard failed his saving throw and became stunned, which includes the incapacitated condition. The fly spell ended, and the fighter fell 60 feet to the ground below. The fighter was not amused, the DM (and many other players) were.
It’s a bit more embarrassing when the spellcaster forgets that they can’t concentrate on two concentration spells at once. While playing Tomb of Annihilation, a druid used conjure animals to summon a Quetzalcoatlus – a large flying dinosaur – and then proceeded to mount it and ride it ahead to scout. Some nearby gargoyles saw this and decided to teach the druid a lesson. The druid cast one of the spells in Xanathar’s Guide to Everything – Earthbind.
It binds a flying creature to the earth. Great idea, but unfortunately it’s a concentration spell. The Quetzalcoatlus disappeared, and the druid fell fifty feet to earth. Luckily, he made his Constitution saving throw and maintained concentration on the earthbind spell!
Kinder DMs will give warnings. I expected the player (who is very experienced and a DM) to remember the rules! There was also the amusement value – everyone, including the druid’s player, was rolling around with laughter for minutes afterwards!
There are a couple of edge cases in what spells require concentration. Although the spell description doesn’t call this out, any spell with a casting time of greater than 1 action requires concentration. So, if you start casting prayer of healing, which takes 10 minutes, any concentration spell you had up will end.
Likewise, readying a spell requires concentration. This tripped up one of my players during recent play of The Rise of Tiamat. The group were fighting two earth elementals, and the high-level cleric banished one of the elementals. The other one disappeared beneath the earth, and the cleric decided to ready sacred flame against that elemental coming out of the earth. Oops! You can’t concentrate on two things at once! The first elemental reappeared and slammed the cleric, and he lost concentration on the readied spell due to the damage, which allowed the second elemental to emerge safely. It hit him as well, knocking him unconscious. Luckily for the cleric, the rest of the group were able to defeat the elementals before he died.
Again, I note that a very experienced DM played the cleric! It’s very easy to forget these rules, especially the aspects that don’t come up a lot of the time.
However, it’s an excellent balancing mechanic. It’s just one you need to be aware of – and its ramifications – when you play a caster who uses concentration spells!
Thanks for pointing out those last two examples (that multi-round casting times and readied spells both require concentration). I had missed those rules, and I was a little skeptical until I looked them up and confirmed them myself. Thanks for laying it all out so cleanly! One thing I’ll note, that I see coming up from time to time on forums and such, is the (mistaken) belief that the first spell you’re concentrating on “continues” for a bit after you’ve cast the second concentration spell which replaces it. People seem to think the first spell lasts until the end of the round, or perhaps that it lasts *just long enough* for the second spell to make use of what the first spell was doing. Neither of which is the case, as I read it.
As much as I like the Concentration feature, I sometimes feel like it is too limiting. It would make more sense to me if long duration concentration spells lingered for players to reuse or refocus after using a short duration concentration spell. After all these spells are balanced in regards to their duration, rather than more powerful 1 action spells. It would also make more sense if a player was able to use two concentration spells as they grew more powerful.
I did play around with the idea of having higher-level spells not require concentration, rather than directly fiddle with the concentration mechanic. There are a few spells where concentration + save ends is a bit overkill, IMO.
I agree. Specifically, hold person allows for a new save every round, while banishment doesn’t. And both of them keep you out of the fight!
If only banishment only worked on extraplanar entities. :/
Overall, I really like the Concentration mechanic. It goes a long way towards balancing casters. I have considered adding a feat which would allow a caster to concentrate on two spells (Multi-Task?), and if they fail on Concentration check for either, they lose it on both. However, I’m worried it could unintentionally break the balance created by the mechanic.
It’s one of those things where HORRIBLE HORRIBLE THINGS could happen if we allow it, but we’re not entirely sure if they will! I haven’t felt the need to tinker, however.
I think concentration was a good idea for the same reasons that it was implemented; however, where I think it fails is the balance in some of the effects. Many of the effects which require concentration are very weak compared to others and simply rarely get used in any serious manner. What I would like to see instead is a new mini-resource system for casters. Allow the pure casters a baseline of something like 3 concentration points and then tailor the spells to use some division of this, such as perhaps haste or fly require 3, but guidance or mind spike only take 1 point while bless and faerie fire need 2.
Three points may not be a gradual enough scale and some testing would be needed, but you could then expand the feature to allow things like equipment, feats, traits, or even metamagic to add a point of concentration or reduce a spell’s concentration cost by a point. This would allow some flexibility in the system without allowing a whole second spell, which will itself then likely only ever get used on the most powerful effects.
Concentration might be a good balancing effect for game play. But story wise it makes no sense at all. What wizard spell designer in their right mind would make concentration part of a spell that doesn’t need it. invisibility… why do i need to concentrate on that, that’s dumb… 5e for me feels more like a board game than any other edition, but then again maybe that’s why it is so popular.
You assume that wizards get to choose what components their spells have. As well you might say it’s dumb some spells require valuable spell components to cast.