Concentration Checks

Just a quick post today. It’s something that came up as I was putting together the rules for spellcasting. The rules for Concentration have changed in the Pathfinder game. This is what they were like in third edition, and this is the newly minted Pathfinder version. In brief: the Concentration skill has been replaced by a level check.

Now, I’m not a big fan of Concentration checks and I’ve been wanting to simplify the system for some time. While I still think that you should be able to disrupt spellcasting, I don’t think the rules for Casting Defensively work particularly well. I don’t think I’ve ever seen a spellcaster fail that check, and it’s just another die roll clogging up an already crowded combat system. So here’s my alternative:

Concentration and Disrupting Spells

It simply isn’t possible for most spellcasters to cast a spell and pay attention to the battlefield around them. Casting a spell while you are within mêlée range of an opponent provokes an attack of opportunity from that opponent. If the attack of opportunity hits (and doesn’t immediately kill or bloody the target), then the spellcaster must make a special concentration check or the spell is disrupted.

The caster must roll 1d20 + caster level + relevent spellcasting ability score modifier (e.g. Intelligence for a wizards, Charisma for a bard or Wisdom for a cleric). The DC of the check is 10 + the damage dealt + the level of the spell you are trying to cast.

If the check succeeds then the spell is cast normally. If the check fails then the spell is disrupted. A disrupted spell has no effect, but it still disappears from the mind of Acquired casters, and still prompts a languor check from Instinctive casters.

Spellcasters can defend themselves against these attacks of opportunity by selecting the Combat Casting feat. Spellcasters with combat casting do not provoke attacks of opportunity when casting their spells in mêlée.

However, even characters with combat casting may still find the spells disrupted by canny opponents. Any attack that strikes and damages the spellcaster during the moment of casting prompts a concentration as above. For spells that are cast as one standard action, the attacker must actively ready an action that is contingent on the casting of the spell. However, some spells take rounds or minutes to cast. Any attack during this time, whether readied or not, calls for a concentration check.

Other distractions: Inflicting physical damage is the most common way to disrupt spellcasting, but it isn’t the only way. The spellcaster might be hit by a non-damaging spell, they might be grappled, bundled to the floor or riding a rollercoaster. In these circumstances a concentration check is called for, although the DCs for the checks differ slightly. See the table below.

Situation Concentration DC
Injured while casting 10 + damage dealt + spell level
Affected by non-damaging spell while casting DC of the attacking spell + spell level
Grappled or pinned while casting 10 + grappler’s CMB + spell level
Inclement weather (wind, rain or sleet) 5 + spell level
Extreme weather (hail, debris, blinding rain) 10 + spell level
Vigorous motion (riding in a wagon) 10 + spell level
Violent motion (on a galloping horse) 15 + spell level
Extremely violent motion (caught in an earthquake) 20 + spell level

 Maintaining Spells: The effects of some spells last for “as long as the caster maintains concentration”. What this means is that the caster is spending some of his attention on maintaining a spell effect. Spending concentration in this way is usually a free action, but this concentration can be disrupted in the same way as normal spellcasting.

And here’s the text of the Combat Casting feat:

Combat Casting [General]
Once you start casting a spell, it is very difficult to disrupt or distract you.

Prerequisites: Spellcaster
Benefit: You may cast spells without provoking attacks of opportunity from enemies in mêlée range. You also gain a +4 bonus to concentration to defend against attacks that try to disrupt your spellcasting.


So what we’re left with is a much shorter explanation of the Concentration system – which can only be a good thing. Casting spells in melee combat becomes an either/or situation: you either don’t have combat casting and provoke attacks of opportunity, or you do have it and don’t provoke attacks of opportunity. There’s no middle ground here.

This fits in with the way that ranged weapons (such as bows) work in melee combat. If you use a bow when there’s someone within melee range of you, then you provoke an attack of opportunity. There’s no roll you can make to mitigate that, you can’t “pull bowstring defensively”. The only way you can use a bow in melee combat is by way of a special ability. The same is now true for spellcasting: you need to have the feat.

The rest of the rules are pretty much undisturbed. I can still ask for a concentration check if I think there is something afoot to distract the spellcaster, and wily fighters can still disrupt the spellcasting of powerful wizards if they are quick and patient enough.

On the whole this change feels right. The number of times as a GM that I have forgotten to ask PC spellcasters to make concentration checks, and forgotten to have my NPC spellcasters make these checks is enormous. I just can’t seem to remember the rule, and the times I do remember it the results are a foregone conclusion. If that’s how the rule for casting defensively is working in practice, then that’s a good enough reason to get rid of it. Yes?

15 thoughts on “Concentration Checks

  1. Food for thought…

    if a fighter in melee combat takes a hit just before he takes his action, why is he not penalised? if he takes damage, it could disrupt his concentration of planned attack manoeuvres.

    in the same way, a spellcaster fires a magic missle towards another specllcaster about to cast a spell, the magic missle should be able to disrupt his concentration.

    I personally think concentration checks should only apply to spellcasting action that takes more than a standard action…which i am to subscribe on the grounds that it just requires more concentration to pull a long casting spell…

  2. To play devil’s advocate: the game assumes that some actions are inherently more complex than others, and that some actions are inherently more unwise than others.

    If two characters are engaging one another in melee combat then their minds are focused 100% on attacking one another. Casting spells doesn’t work that way. A spellcaster is thinking about the complex gestures he needs to cast his spell, the special words he has to say, where his wand is pointing… as well as trying to remember what the opponent with the massive club is up to.

    Casting a spell that takes one standard action is just as complex a task as casting a spell with a casitng time of 1 hour. It’s just that the window of opportunity to disrupt the spell is smaller.


    Let’s say your right. But rather than say impose opportunity attacks on warriors, why bother having them in the system at all? Aren’t they just a pain in the bottom to adjudicate. Why not excise the rules for attacks of opportunity completely? It would make for a much simpler system.

    A step further than I was willing to go with the Pathfinder rules. But why not?

    • right ok lets try this differently…

      ask a fighter to cast a spell, he will fumble as he is not trained in the art

      ask a spellcaster to wield a sword, he will fumble as well as he is not trained in the art

      but each of the class are proficient in the art they are trained, and therefore they should be equally challenged for attack disruption or not be challenged…

      an action in combat last 6 seconds, it doesnt say a fighter takes 1 second to hit a target and spellcaster takes the whole 6 seconds to cast a spell…a caster could take a split second to offload the 1st level spell from his head and fighter could take 4 seconds to pull off his 15th level multiple attacks, each action has its complexity and should be penalise equally as they cant be quantified in a game…i am using time as a means to describe where the longer the gap the likelihood that an action can be disrupted…

      i think concentration check is an unfair an unnecessary action in combat and why waste time by taking a step further just for the sake of it…

    • Sadly, I disagree. I think it takes far more knowledge, skill and concentration to cast a spell than to swing a sword. I think it should be inherently more difficult to do so.

      However, the rules I’m proposing remove the need for spellcasters to make concentration checks during combat – unless someone is deliberately trying to disrupt their spell. I’m not sure whether you agree with what I’m propoing or not!

      It seems fair that a well timed blow can disrupt spellcasting. In the same way fighters can be “disrupted” from making their attacks. They can be distracted, or tricked…. it’s just we don’t use the concentration rules to govern these things. They come off combat manouevres like trip, or stun or feint.

      • Spellcasting in 3.5 is also considered to be inherantly more powerful than bashing people on the head with sticks (which it is), that’s why Arcane Spell Failure and Concentration exist; they’re -supposed- to be penalties to casters to bring them more in line with martial classes: Moar power, but more restrictions.

        Of course, it doesn’t actually work like that in practice, but you know.

        That’s also why concentration doesn’t exist in 4e; spells in 4e are of equal power to martial abilities of the same level, so concentration is unneccessary.

      • I am doing a major overhaul, but the spells aren’t really going to be any more balanced with the martial abilities than they are now. This is still the third edition game after all!

  3. This isn’t going to scale at all. Even a mid-level character can reasonably expect to take 20 or more damage from a single hit, making it completely impossible to succeed on the concentration check.

    If you’re going to include damage as part of the DC, you’re going to need something the caster can add to the check that scales at approximately the same rate as the average amount of damage a level equivilent enemy does, because as it stands the DCs will typically end up flat out impossible to achieve, which begs the question of why even bother making the check in the first place.

    I’d probably look into removing the check entirely; work out some sort of semistatic number (say 1/4 max HP or something) and if the attack does more damage than that, the spell is interrupted, otherwise it’s unaffected. It’s certainly a lot cleaner and faster than having a check in there which is going to be completely pointless past around level 7ish.

    • No, it’s not likely to scale. But they are the rules as published in the Pathfinder rulebook. The rules are a little harsher than third edition where the DC was 10 + damage dealt (as opposed to 10 + damage dealt + level of spell you’re casting).

      I quite like the idea that disrupting the casting of spell should be fairly easy if the fighter is in the right place at the right time. After all, these aren’t circumstances that are likely to come up very often. And a skill check does seem more appropriate.

      One of the issues I had with 4th edition was they way the static defences replaced saving throws. Sure, they made the game quicker but they also took away a certain amount of drama. Sometimes the stakes are just so high that you don’t want the GM rolling the die, you want to put that d20 in the hands of a player and tell them to make a saving throw. It makes success or failure firmly the responsibility of the player. And that’s the way I see concentration checks.

      Maybe the wizard has to finish casting his teleport ritual so the party can escape from an onrushing horde. Suddenly, everything is down to how well he’s rolling his concentration checks – not how well the GM is rolling for damage.

      I do take your point about scaling. Having had a party of 6th level adventures catch a 20th level wizard with his pants down (they kept disrupting his spells and eventually killed him), they is a need to make the concentration checks scale a little.

      The problem here is that the damage from fighters doesn’t really scale as they gain levels. Yes, they do more damage – but that’s largely because they make more attacks. Disrupting spellcasting is a single attack on a single point of initiative: fighters can’t take advantage of their full attack action in this case. And while yes: a 20th level fighter does do more damage with one attack than a 1st level fighter, he doesn’t do proportionally as much more damage than a 20th level wizard can do with a spell as compared to a 1st level wizard.

      That was a very confused sentence. But you get the point.

      Maybe the way forward is to change the way the Combat Casting feat works. Perhaps instead of a flat +4 to concentration checks it should be some figure that scales as the wizards levels. The trick is going to be coming up with the right figure.

      • but bare in mind, fighter’s attacks are not subject to saving throws whereas most offensive spells are….

        scaling combat casting is one way to go about it, but then again that would make it more than just a feat…perhaps the role the the spellcaster makes should scale better as he gain level…

      • i can only suggest we test your system thoroughly in April at the next retreat, and then you can take a decision with our input whether we should change or not

      • The thing is though; Pathfinder has the Concentration skill. So long as that skill exists, 10 + damage is difficult, but doable against appropriate enemies if you have max ranks in Concentration and a few items to boost it.

        I’m not saying “You should remove Concentration checks entirely.” i’m saying “If you remove the Concentration skill, you need to replace it with something, otherwise Concentration checks become a pointless waste of time.”

        Concentration is the single most important skill a caster can have, if you just remove it without changing the damage ratios (and making the check DC harder at the same time) all you’re really doing is saying “I don’t want casters to be able to cast spells while inside melee threat ranges, even if they want to.”

  4. Pathfinder doesn’t have a Concentration skill per se. They replaced it with a level check + ability score modifier. So it’s effectively a skill in which all casters have maximum ranks without having to spend any skill points.

    Other than a change in a few DCs, the Pathfinder system works in exactly the same way as third edition, except a roll on the Concentration skill has been replaced with a level-based “concentration check”.

    What I’m proposing is to leave the entire system of making concentration checks untouched except for one area: casting spells defensively. According to rules a concentration check needs to be made to cast a spell while threatened in combat without provoking an attack of opportunity. The DC for the check is 10 + spell level in third edition, or 10 + twice the spell level in Pathfinder. I think that’s an unnecessary roll. Everything else is probably fine, but casting defensively is the part of the concentation rules that I find pointless.

    This leads to two choices:

    1) We get rid of casting defensively entirely, and just say that spellcasters can cast their spells in combat withour provoking attacks of opportunity.

    2) We say that spellcasting in combat always provokes an attack of opportunity. However, if you have the feat Combat Casting then you don’t provoke these attacks.

    At the moment, I’ve gone for option 2. But Option 1 is certainly a possibility.

    • Oh really? Pathfinder killed Concentration? I’ve played over a dozen Pathfinder games, how did i not notice that.

      In that case, i retract my objection.

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