What is a concentration check?

Concentration check is a particular type of Constitution saving throw that spell-casters make whenever there is any doubt.

They are correctly maintaining their focus on a cast spell that requires it.

Spells requiring concentration of the caster are a sub-type of periods that share many properties in common:

The caster can only use his concentration to focus on one focus spell at a time.

The caster’s concentration must be maintained for the spell duration; otherwise, the spell will not work. It only applies to periods of engagement, the time of which requires concentration.

Although many spells usually have a cast time (the most common in general), bonus action, or reaction, some focus spells have a longer cast time, which requires focus. Then the caster must focus on the entire cast time, rather than the duration, for the magic to work.

If the caster fails to focus when the spell requires it, there is a chance that he will die.

A focus spell can fail if the caster takes any amount of damage in this case, he makes a concentration check (Constitution saving throw) with DC = greater than 10 or 1/2 damage.

A concentration spell can also automatically fail if the caster casts another focus spell, becomes incapacitated, or dies.

When is Concentration check required?

  • Concentration check is obligatory for most spells in D&D 5e covering lengthier than one try.
  • But it’s not all-inclusive. However you have a concentration spell casted, you can still cast non-concentration spells, swing a sword, or have a conversation.
  • You would usually be able to do, except casting more concentration spells.
  • Concentration is the mechanical check. It confirms that the caster knows the effort required to sling spells.

Different Types of Concentration Checks

  • When you take destruction or are suitably surprised, you will have to make a concentration check to avoid dropping the spell entirely.
  • There are three possible concentration checks:

Damage based concentration checks

  • When you have to roll a Constitution Saving throw vs a DC of 10, or half of the damage engaged, either of the two is greater.
  • If you produce damage from multiple sources, roll a check from each.

Shock/Instability based concentration checks

  • When some moving part of your environment reasonably obstructs  your capability to concentrate. This is another check, with a regular DC 10.
  • Normally it is not small things like thunder or sudden darkness, but it’s at your DM’s discretion.

Auto-fail concentration checks

  • They are not really “checks”, it cause you to automatically descent concentration. Dying, or dropping to 0 HP and becoming debilitated both the dropping concentrations.
  • But so try to cast another concentration spell.

Why is Concentration Check required?

  • Some spells require you to maintain focus to keep their magic active. If you lose focus, then the period ends.
  • If a while is to be supported by focus, this is indicated in the Duration field, and the spell identifies how long you can focus on it.
  • You can end a concentration at any time (no action is required). Regular activity, such as moving or attacking, does not interfere with concentration.

Factors breaking a concentration

Cast another spell that requires concentration.

  • You lose a spell’s focus if you cast another spell that also requires focus. You can’t focus on two periods at the same time.

Take damage.

  • Whenever you take damage while focused on a spell, you must make a Constitution saving throw to maintain your focus.

The DC is ten or half the harm you take, whichever is greater.

  • If you carry liability from multiple sources, such as an arrow and dragon’s breath, you must create a separate saving throw for each source of damage.

You are unable to act or dead.

  • You automatically lose your spell’s focus if you are unable to work or if you are finished.
  • The DM may also decide that certain environmental phenomena, such as a wave crashing into you while on a storm-tossed ship, involve succeeding on a DC 10 Constitution.

Does Tireless Logic work on a concentration check?

  • The benefit of the tireless logic trait cannot be applied to concentration tests.
  • While the benefit of unwavering logic suggests that it allows you to re-roll a skill test or an ability test, a focus test is neither.
  • Although the term “ability test” is not clearly defined by the rules. Ability test is quite different from a focus test and a caster level test.
  • However, the earlier version of D&D 3.5 Pathfinder clearly defines an ability test: “An ability test is a roll of 1d20 plus the appropriate ability modifier”.
  • It’s unlikely that Paizo expanded that definition to include focus checks, which are a vital creature ability plus caster level.

Is there a way to cast a focused spell without having to focus on it in D&D 5E?

  • Yes, you can use the Spell Gem featured in the WoTC Out of the Abyss mod.
  • Like the glyph of protection, it stores a spell up to a certain level (depending on the stone’s quality).
  • It allows you to cast a saved spell using only 1 action:

Spell stone

  • Excellent item varies (requires caster approval if you wish to infuse the gem)
  • A spell stone can contain a spell from any spell list. You will learn about the spell when you know the properties of the stone.
  • While holding the gem, you can cast a spell as an action if you know it or if it is on your class’s spell list.
  • It does not require any components and does not require approval. Then the spell disappears from the stone.
  • If a spell is of a higher level than you can usually cast, you must create an ability check using your spell-casting capability to determine if you successfully threw it.
  • DC is 10 + spell level. On a failed save, the spell disappears from the stone with no other effect.
  • Each spell stone has a maximum spell level that it can store.
  • The spell level determines the rarity of the rock and the saving throw DC and the saved spell’s attack bonus, as shown on the spell gems table.
  • You can fill the stone with a spell if you are listening and it is empty. To do this, you cast a spell while holding the stone. The magic is stored in stone instead of affecting.
  • Casting a spell must take 1 action or 1 minute or more, and the spell level must not be higher than the stone’s maximum.
  • If the spell is of the school of renunciation and requires consumable material components, you must provide them, but they may cost half the typical cost.
  • Infused with a spell, the stone cannot be refilled until the next dawn.
  • The deep gnomes have created these magical gems and are keeping the process a secret.

Is Magic Missile the best anti-focus spell?

  • Whenever the caster takes damage while focusing, he must initiate a focus check. DC is equal to 10 or half the damage taken (whichever is greater).
  • If you take harm from multiple sources, such as arrow and dragon’s breath, you make a distinct saving throw for each source of damage.
  • At level 1, the magic missile fires 3 different missiles. These missiles can target any combination of enemies the launcher desires.
  • They never fail and have a range of 120 feet. At each level above, the magic missile fires another projectile. All missiles strike simultaneously.
  • Suppose each missile counts as a separate source of damage (comparable to a fighter’s multiple attacks, multiple burning beams, or four meteor swarm hits).
  • In that case, Magic Missile is the best focusing destroyer in the game.
  • The caster hit by each 1st level magic missile projectile must perform 3 consecutive DC10 focus checks.
  • Even assuming they have a +2 Constitution converter, it has a 72% chance to break their focus.
  • An upward-pointing magic missile could easily penetrate legendary resistances.