D&D 5E Player character lv 10 wizard who is also smart player how to challenge?

[Doug McCrae]

Illusions of monsters, or the non-magical equivalent (like scarecrows), will cause the wizard to waste spells.

 

[Quickleaf]

Ways to make running NPC casters easier:

• Reduce their spell selection to whatever you consider are the essentials. You realistically probably aren't going to need an arsenal of 12+ spells. All you really need are maybe 6-9 (if that).
• Write out their spell descriptions in abbreviated one-line format so you can see at a glance what that NPC caster can do.

Spoiler: Example of short-form spell descriptions

In this case, this Red Wizard Diviner was exploring a ruined city while the PCs were exploring said city. Very much like the Nazis in Indiana Jones. The black circles / bold spells indicated spells she routinely cast, and thus would not have those spell slots available. In this case, because the Red Wizards were an ongoing enemy, I opted to give the Diviner the full spell compliment. However, if they'd been a one-shot enemy, I'd probably have reduced her total prepared spells by half (i.e. down to 9).

Cantrips: Green Flame Blade, Light, Mage Hand, Message, True Strike*
1st Level (O O O ︎)

• Detect Magic* [ritual]
• Feather Fall: reaction; 60’; 1 min; 5 falling creatures instead descend 60’ per round, taking no damage.
• Mage Armor: 1 hr, armor-less target gains AC 13 + DEX.

2nd Level (O O ︎)

• Detect Thoughts*: 30’; Conc. 1 min; surface > DC 15 WIS save.
• Locate Object*: Conc. 10 min; sense familiar object 1,000 ft.
• Mind Spike*: 60’; Conc. 1 hr; 3d8 psychic, DC 15 WIS half, on fail always know target’s location while on same plane.

3rd Level (O O ︎)

• Clairvoyance*: 10 min; 1 mile; Conc. 10 min; invisible sensor.
• Fly: Conc. 10 min; touched creatures gains fly 60 ft.
• Fireball: 150’, 20-ft radius sphere, 8d6 fire, DC 15 DEX save for half damage.

4th Level (O O ︎)

• Arcane Eye*: 30’; Conc. 1 hr; invisible darkvision eye, 30 ft.
• Ice Storm: 300’; 20’ radius, 40’ high cylinder, 2d8 bludg. + 3d6 cold damage, DC 15 DEX save half, difficult terrin u.e.o.y.n.t.
• Stoneskin: Conc. 1 hr, resistance non-magic B/P/S damage.

5th Level (O ︎)

• Rary’s Telepathic Bond*: [ritual] 30’; 1 hr; link 8 willing creatures.
• Scrying*: 10 min; Conc. 10 min; see PHB 273

6th Level (O)

• Mass Suggestion: 60’; 24 hrs; 12 creatures DC 15 WIS save.
• True Seeing*: 1 hr; touched creature Truesight 120 ft.

7th Level (O)

• Delayed Blast Fireball: 150’; Conc. 1 min; 20-ft radius sphere, 12d6 fire, DC 15 DEX save for half damage; +1d6 delay…
• Teleport: her and 8 allies within 10’, see PHB 281

Things that make counterspell interesting:

• Foreshadow the possibility of a counterspell using enemy, and include NPC/scenario-specific ways to "deactivate" the enemy's counterspell ability (e.g. getting an aasimar divine soul sorcerer to lie might prevent him from counterspelling for a time, while a necromancer might be prevented by stealing the special skull arcane focus he uses for counterspelling).
• Have dramatic side effects every time counterspell is cast. Think Harry Potter wizard duels. When an enemy counters his fireball, maybe sparks go flying midway between the two wizards, igniting combustible materials or causing a curtain of steam upon contact with water.
• To enforce caster themes, only have enemy casters counter spells which are appropriate to their theme (e.g. a fire or water mage – or an abjurer, I guess – might reasonably counter a fireball, but if the mage is an enchanter, I would not have them case counterspell vs a fireball, even if they could).
• Create environments & enemies that interact with the counterspell rules. For instance, I had fire mages who, if they successfully countered your spell, you took d6 fire damage per level of the spell you attempted to cast. They were paired with a magically charged citadel which – the more counterspell was cast – the greater the odds that the next counterspell would cause a magical eruption that birthed a living spell.

Things that muck with the greater invisibility + fireball tactic:

• An invisible wizard with a poor (or no) Stealth roll being noticed by monsters with good passive Perception. Invisible =/= Hidden.
• Determine starting encounter distance randomly and/or using terrain or weather conditions that make encounters start much closer than 150 feet away (fireball range). Looking at the official DM screen most encounters start much closer than that.
• Monsters with blindsight, tremorsense, or truesight.
• Monsters with Spell Reflection (e.g. spectator).
• Storms or other ongoing hazardous environments / damaging terrain that force concentration checks
• Having innocents or creatures whom PCs are being paid to rescue among the monsters. Using tents and limiting line of sight to make targeting with a fireball a generally risky proposition.
• Present combat objectives that are not just "kill all monsters." For instance, if the PCs need to keep a low profile (e.g. to avoid alerting a larger enemy force or to avoid violating a treaty) then fireball should be avoided unless absolutely necessary.

Handling Banishment, Polymorph, or Wall of Force on Solo Monsters

• Unless the monster is intended to be a boss, I view using these sorts of spells to circumvent a fight with a troll as an entirely appropriate use of the player's resources. After all, the spell might fail (due to the monster succeeding a save), and the wizard has expended a resource.
• Look at how many encounters you're running the players through each adventuring day. If it is routinely falling considerably short of 6-8 encounters (which the game is built around), then I recommend making the few encounters you do run much more dangerous. That way expending resources like spell slots will matter.
• If it's a boss monster, then these are the sorts of spells to use Legendary Resistance to automatically save against. If the boss monster lacks Legendary Resistances, then it needs more customized defenses – maybe it has the power to planeshift on its own will in a way that breaks banishment, or maybe it has the golem's Immutable Form trait making it immune to polymorphing, or maybe it can burrow or fly or teleport or cast dispel magic to escape a wall of force.

 

[Eltab]

I pestered the heck out of an L14 group with some Lizardmen javelin-throwers in a lake. They would pop up, throw, dive. It took the Rogue wading out and held-action Sneak Attack to damage one. The Ranger did same with a bow and the wounded Lizardmen swam away.

Can you Misty Step through a Wall of Force?

Invisible Assassin at a doorway with orders to take down the Wizard.

Two or three big bruisers who show up from the opposite side of the chamber when they hear the party get into combat with the cannon fodder.

A common thief gets into the Wizard's room while he sleeps and steals his spellbook and component pouch. By the time you can cast fifth-level spells there should be a BBEG lurking in the background who wants to learn the PCs' weaknesses.

 

[Esker]

Others have already given good tips, but my advice:

* A level 10 wizard is supposed to be able to shut down / trivialize an encounter when they use their biggest spells. As you said, occasionally having a spellcaster with Counterspell is fair game, but doing this all the time is bad form. The same would apply to other strategies: don't try to have a countermeasure ready every time or it will feel like you're invalidating what should be a powerful character.

* That said, sometimes you can have counterspellers, or casters with disintegrate, or even brutes with an innate Fey Step type ability, or a burrowing speed, or who can shapeshift into a creature with a burrowing speed, who can escape a Wall of Force. No powerful ability should be countered constantly, but no powerful ability should be 100% unstoppable either. Ideally, when the wizard has used one of his top level resources, monsters who can escape should have to use some of their precious resources to do so as well --- disintegrate is a 6th level spell, and getting an enemy caster to burn a 6th level slot would be a good consolation prize. But again, don't do this too often (and if the encounter is unimportant enough that wall-of-force-ing everybody and walking away is a viable option, just let them! Reserve your countermeasures for foes that need to be defeated.)

* Wall of Force usually can't take somebody out; it's a divide-and-conquer strategy. Neither side can target anybody on the other side with anything, but the creature(s) trapped inside still get actions, which they can use to buff themselves, so the party has a tougher foe to face when the spell ends. This is again an easier proposition for a caster than a brute, but monsters can have any abilities (or potions of growth/flying/invulnerability) you want. A potion of invisibility and the hide action is a good way to mitigate the 'readied actions when the wall drops' issue.

* Intelligent enemies who aren't trapped would know to focus fire on the wizard to make him lose concentration.

* At level 10, Wall of Force can only be cast twice, maybe three times a day (if the wizard uses arcane recovery on another 5th level slot). Make it tough to decide whether a given fight is the right time for it. Even if you're not in the habit of running a lot of combat encounters in a day as the norm, if you have one or two days where the PCs have to slog through a lot of combats between rests, they will think more carefully about going nova. Intermittent and unpredictable reinforcement is the best way to shape behavior.

 

[Shiroiken]

In general, your issue is primarily the Five Minute Work Day, where the party goes nova (uses most of their good abilities), then rests to get them all back. Spellcasters are the strongest characters when allowed to do this, as almost all their abilities require long rests. If you made even just 4-5 combat encounters, plus a few non-combat encounters when spells would help, you'd wear down his spells over time. There are various solutions on how to avoid this, but it depends on your style as a DM and how you approach your game.

Oh, and you can always use a beholder behind a bunch of minions to make him cry

 

[Ashrym]

Use more tight spaces and twisty areas. Limiting the range of visibility limits the range of detection and starting encounter range when both sides are acting stealthy. It's harder to fireball minions when they are already in your face or the encounter area is only 20' roundish already because of friendly fire.

That also helps with the improved invisibility. A close range encounter that starts with the wizard using his turn to cast a defensive spell starts with determining when he takes that first action so if the situation suits surprise checks it's not that hard to surprise the wizard often enough. No action first round, takes a beating. If initiative was also lost takes a beating the second round too before the defensive spell is up. Doesn't take an offensive action until round 2 or 3 depending on surprise either way. Make sure the opponents are using that delay effectively. (Or laugh when the rest of the party destroys that monster while the wizard turns invisible and hides.)

Don't give the wizard a target he can attack. Bow range is greater than spell range for the vast majority of spells and walking into a room that erupts into a stinking cloud spell while the door close allowing 7 rounds before the room fills with sand gets a bit more problematic. There are things the wizard can do in that situation but it's not as easy as "I magic missile the darkness".

Create an encounter with timed events on specific rounds, like reinforcements from x area arrive on round 3 or 4. On round 6 y trap is armed and triggered if the kobolds from z area are not dispatched first.

Encounters are as basic or complex as the DM decides to design them. Ultimately the goal is resource attrition so it doesn't matter if it's 8 combats over the course of the day or 1 massive complex battle with waves of opponents and triggered events (at least as far as the wizard is concerned -- too many single big battles is hard on short rest classes). Mixing up both styles helps to vary combat and if the wizard doesn't know how many combats to expect then it's harder to determine when to blow through slots.

Play the occasional drawn out running the clock where long resting isn't an option and the day is 14 battles long. The thing to keep in mind is just because the game session only have 1-2 encounters doesn't mean the characters are getting a long rest every session. It's pretty normal in the game I run for starting off a new session from a point in the previous session that did not provide a long rest in between.

Start a session with assassins attacking while the party is resting and interrupting that long rest. No rest means no resource recovery. Don't abuse that. It's interesting used once, maybe twice with a long gap in between.

Add a lot of social and exploration encounters. Wizards have tools to handle those but charms tend to let the target know what happened after the fact and multiple exploration challenges can eat through slots that will no longer be there for the combat encounters. And even wizards can only prepare for so much.

The short answer is "variety".

Hope that helps.

 

[Kurotowa]

I have two pieces of advice, the first of which others have already given.

Long rest casters like Wizards shine the fewer encounters there are between long rests. They can dump all their high levels spells right away to dominate battles and often end them decisively. To challenge them you need multiple smaller encounters strung together so that if they blow their big spells in the early encounters they have to get by without them in later ones.

The other more general piece of advice is, you don't challenge PCs at their strong points, you challenge them at their weak points. Their strong points are what they do that makes them feel cool and powerful. If you undercut those it just gets you in an arms race with the player to become even stronger. So let them enjoy their strong points. Instead, mix events that let them demonstrate their strong points with encounters (combat or otherwise) that force them to engage with their weak points. That's when you get them to scramble to overcome a disadvantage and really put them on the back foot, all without making their characters feel less competent at their specialties.

 

[Ogre Mage]

The beholder is a deadly opponent for a spellcaster due to it's 150 foot antimagic cone. At CR 13 it is not out of bounds for a 10th level party.

The rakshasa is another deadly opponent for a spellcaster because it is IMMUNE to spells of 6th level of lower unless it wishes to be affected! Also CR 13.

The arcanaloth has truesight (120 ft.), magic resistance, teleport at will and counterspell. CR 12.

The erinyes has flight (60 ft.), truesight (120 ft.), magic resistance and is proficient in Dexterity, Constitution, Wisdom and Charisma saving throws! It can attack in melee with its longsword and at range with its longbow. CR 12.

 

[Dausuul]

As others have said: Your main problem is that you're letting the wizard rest after every 1-2 battles, so his big guns are always loaded.

I have found the most effective solution is to create adventures where the party is on a strict time limit. You have 2 days to kill the evil sorceress before the portal to hell opens. Once you unseal the tomb of the vampire demigod, you have to reach him and stake him before sunset. The phantom city will vanish on the third midnight and won't return for a thousand years, so you have to get in, find the MacGuffin, and be gone before then.

This forces the casters to ration their spells and rests, and they can't just go all-out in every battle.

 

[Flamestrike]

I think I need to change my tactics and have more smaller encounters I have a hard time gauging what to throw at them without overtaxing them that they do not continue to adventure and try to long rest after every fight. I think I will review the encounter building in the DMG. I don't really fully understand encounter building but I suppose its one of those things you get better at with time and experience?

Why are you letting them?

You're the DM arent you?

Put them on the clock. 'Save the princess by time X or else [bad thing] Y happens'. 'You have 24 hours to escape the dungeon or else [bad thing] Y happens.' 'You must stop the ritual by midnight or else a CR25 Demon lord is summoned.' 'You need to recover [macguffin]. If the BBEG is alerted, he will teleport away. Time is of the essence.' Etc, etc etc.

Put them on the clock. From there, let them marshal their resources as they see fit.

If that doesnt work (or you lack the imagination to come up with a valid in game reason), just say 'No' you cant long rest now. It's much more heavy handed but screw it. Alternatively, if you want a mechanical solution, simply make a rule that 'resting' no longer recovers anything. You just get get an automatic 'short rest' recharge after 2 encounters, and an automatic 'long rest' recharge after 6 encounters.