Showing posts with label Mechanics. Show all posts
Showing posts with label Mechanics. Show all posts

Monday, September 17, 2012

Ability Scores are Obsolete and Stupid

As I said last post, I've simplified the fourth edition character sheet a bit. Its only a small change, but it saves you a bit of headache, and makes character creation take a little less time (okay, DnD char-gen will always be a time-consuming nightmare, but this helps a bit).

Basically, since the beginning of third edition there has been no reason for ability scores to exist in their traditional form. Except for very few cases, the only thing you use is your ability bonus (your ability score -10 /2); the score itself is just a clunky and totally unnecessary detour before arriving at the bonus, an artifact of first and second edition that no longer makes sense.

So, just get rid of them. Ability Scores and Ability Bonuses are now the same thing. Instead of 10 being the baseline for abilities, its 0. For instance, I usually used to have my players start all their ability scores at 8, and then give them 28 points to distribute (with every point increase above 14 in one stat costing double). Nowadays, I tell them to start at -1, and give them 14 points to distribute with the cost doubling after 2. Each racial and leveling bonus adds +1 to the ability stat, rather than the default +2.

The only place where this doesn't work is when you're determining your starting hit points in fourth edition (not a problem if you're playing third). There are two solutions to this.


  • Double your CON score and add 10 when using it to determine starting hit points.


or the much more elegant


  • Just replace Constitution with a set number for this purpose (I use 15). Its not like the variance in starting hp matters after the first few levels anyway.

Like I said, it's not an amazing revolutionary change that fixes everything. But I do like it better than the default.

Thursday, September 13, 2012

The Players Roll All the Dice

Finally back to this blog. I've done some editing on the earlier monster entries, and finally added the lore and descriptions for the Mummy entry (check it out; I'm quite proud of it).

More importantly though, I've been trying out some new houserules with my group that turned out to be a great success. Allow me to share them with you.


Let the Players Roll All the Dice

This is really extraordinarily simple; I'm surprised it hasn't been popularized before. One of the most annoying things about playing D&D is the sheer number of things determined by the Dungeon Master's die rolls. Every time something happens to the PC, its up to the DM's dice. If you're attacked by a monster, you just sit there and wait for the DM to determine if you get hit or not. If you're using a passive Perception skill, you just stare at the number on your character sheet and hope that its higher than whatever the DM rolls.

With this houserule, every die roll that involves conflict between a PC and an NPC is rolled by the player. The character sheet no longer has any static values (well, aside from hit points). The monster stat blocks no longer have any d20 modifiers. If the paladin is getting stabbed by an orc, the player rolls 1d20 and adds his armor bonus in hopes of beating the orc's static attack value. When his paladin counterattacks, the player is still rolling the dice, making an attack roll against the orc's static AC as per usual.

Its super easy. Just tell your players to subtract 10 from all their defenses and passive skill values (in fact, you can just cross out "passive perception" and "passive insight" on the sheet entirely), and draw a little + sign in front of the remainder. On the DM's side of things, add 10 to the attack and skill bonuses of all the monsters and remove the +. In most battles, the Dungeon Master will not roll a single d20.

I've found that doing things this way makes the players feel more engaged in the combat. It also makes them feel more in control of their characters' safety, even if the dice are still random.


Sometime in the next few posts, I'll share another new houserule of mine, this one related to simplifying the frankly bloated character creation process.

Saturday, July 16, 2011

Upgrading and Downgrading Monsters

As the PC's grow in power, enemies that were once overwhelming threats become less and less frightening. Nothing makes your players more satisfied than just barely persevering over a single, powerful monster at level 5, and then hacking through a swarm of those same monsters at level 15; it really gives them a sense of how much more powerful their characters are becoming.

Unfortunately, throwing a bunch of level 5 solo monsters at a level 15 party isn't going to make for a fun encounter; it will just take the PC's forever to whittle down the monsters' hit points, and the monsters' inability to hit the PC's will remove any element of challenge. Furthermore, solo and elite monsters have a lot of actions each round, and you as the DM probably don't want to be running eight of them at a time. So, here's a fast and dirty rule for using the same enemies at different levels.

  • Create a Minion, Lesser, Normal, Elite, or Solo version of the monster that's worth the same amount of XP as the original.
Let's say your PC's fight an elite orcish warrior at first level (200 xp). A fifth level normal monster is worth that same amount of XP, so you could take that elite orc, raise him to fifth level, and then downgrade him to a normal monster. When the PC's reach mid heroic tier, they find themselves facing what is undoubtedly the same monster that they did at level 1, but now they can handle more of them. They fight large groups of these orcs at level 9 (a level 9 lesser monster is worth 200 XP), and then crowds of them at level 13 (minions).

For another example, let's say you plan for your campaign to end with the PC's going into the Abyss to slay a demon lord. To give them a preview of the horrors to come, you might take a nycademon (level 22 monster, worth 4,150 XP) and have them fight a thirteenth level solo version of it (4,000 XP. Not exactly the same, but close enough for government work) at late heroic or early paragon tier. Fighting this apparently mighty demon and then learning that the ultimate villain's lair contains armies of them will give the PC's a sense of scale, and make them feel totally badass when they really are powerful enough to face armies of nycademons.

At early levels, XP awards for monsters at different levels tend to be divisible. This breaks down at higher levels (as per the example of the nycademon above), but as long as its close enough to the same number of XP, it works. A good guideline is:

  • A minion is four levels higher than a lesser. A lesser is four levels higher than a normal. A normal is four levels higher than an elite. An elite is five or six levels higher than a solo.
That's the premise. Now to go into the execution. The DMG provides rules for upgrading or downgrading a monster by changing its defenses, hit points, and other statistics. If you're changing them more than five levels or so, you will also want to adjust the damage done by their attacks as per the table on page 185 of the DMG (be aware, though, that this table errs on the forgiving side. Use it as a guideline, but most of your monsters should do slightly more damage than it says. If you have access to DDI, there are updated damage tables that work much better). The hard part is changing the monster's "grade" (elite, minion, etc). This isn't an exact science, but here's a basic template that I've found to work well.


Creating a Minion
  • Raise the base monster's level by eight.
  • Give it only one hit point, and remember that minions take no damage from an attack that misses.
  • Look at the expected damage values for a monster of the creature's (new) level, and have its attacks do a static number toward the bottom of that range (for instance, if a level 1 monster is expected to deal 1d10+3 damage with a typical attack, a minion should deal 4 or 5). The damage can be a point or three higher if your minion is a Brute.
  • Take away any recharge powers, and leave it with (at most) only a single encounter power.


Creating a Lesser
  • Raise the base monster's level by four.
  • Reduce its hit points to half of its new expected hit point total, and remember that lesser monsters are instantly killed by a critical hit.
  • The monster automatically fails all saving throws.
  • Look at the expected damage values for a monster of the creature's (new) level, and have its attacks do a static number toward the lower-middle of that range (for instance, if a level 1 monster is expected to deal 1d10+3 damage with a typical attack, a lesser should deal 6 or 7). The damage can be a point or three higher if your lesser is a Brute.
  • Take away any recharge powers, but leave its encounter powers (watering them down as necessary if they're too powerful for a lesser).

Creating an Elite
  • Lower the base monster's level by four.
  • Give it one of the templates from pages 176-184 of the DMG.
  • Alternatively, you can wing it on your own by doubling the monster's (new) hit point total, raising three of its (new) defenses by 2, giving it a +2 bonus to saving throws and an action point, and then making up some new abilities for it. In essence, you can create your own "template" tailored specifically for this monster. If you're going this route, you should make sure that the monster can make more than one attack per round, and that it has some kind of reaction or interrupt ability (preferably movement related).

Creating a Solo
  • Lower the base monster's level by nine or ten.
  • Quadruple its (new) hit point total.
  • Raise three of its (new) defenses by 2.
  • Give it a +5 bonus to saving throws.
  • Give it two action points.
  • Some of its encounter powers should become rechargeable.
  • Give it one of the following two abilities:
Double Actions (passive): instead of rolling for initiative, the monster has two initiative scores. One equal to its expected initiative bonus +5, the other equal to its expected initiative bonus +15. On both of these turns, the monster can make a minor, a move, and a standard action. The monster can make saving throws and recharge rolls only on its higher initiative. If the monster inflicts or recieves a status effect that lasts until the beginning or end of its next turn, make it last until the turn after its next.

Or

Spawn Minions (minor; once per round): a minion three levels lower than the monster appears in an adjacent square and acts after the solo monster's turn. Do not award XP for defeating these minions. Note: you should add the "leader" sub-role to your solo monster's description if you give it this ability.


Note that for all the above examples, I've been assuming that the base monster is a Normal. You can reverse engineer these steps to turn an elite into a solo, a solo into a normal, a minion into an elite, etc.


An Example

One of the first monsters I created for this blog was the Stone Archon Fleshmasher, a level 16 normal monster. For this post, I made a version of this creature at every grade, scaling them to the appropriate levels for the creature's XP value. The elite and solo versions were made using the Fighter class template from the DMG.


Stone Archon Fleshmasher; Level 6 Solo Soldier (1,400 XP)
Medium elemental humanoid (earth)
____________
Initiative see Double Actions below Perception +9 (tremorsense 5)
HP 272; Bloodied 136
AC 24 Fortitude 23 Reflex 17 Will 20
Speed 5 (increase to 6 while bloodied)
Skills +12 Religion
Saving Throws +5
Action Points 2
____________
Passive
-
aura Battlefield Awareness aura 2; enemies within the aura are marked by the archon.
-
Double Actions
The archon has two initiative scores: one at 21, the other at 11. On each of these turns, the archon can make one standard, one move, and one minor action, but it makes saving throws and recharge rolls only on its first turn each round. Effects that last until the beginning or end of the archon’s next turn refer to its next turn on that initiative.
-
Combat Superiority
If the archon hits with an opportunity attack provoked by movement, the enemy stops moving.
____________
Standard Actions
-
basic melee attack Flail (at will):
reach 2; +13 vs. AC; 2d6+4 damage; if the target is slowed, it is now immobilized until the end of the fleshmasher’s next turn. If a creature is killed by this attack, its body turns to stone.
-
melee Swishing Flail (at will):
Make two flail attacks against different targets.
-
blast Avalanche (recharge 4, 5, 6):
Close blast 6; +13 vs. Reflex; 2d6+4 damage and target is restrained (save ends).
____________
Move Actions
-
Earth Mastery (recharge 4, 5, 6):
Teleport three squares and make a basic attack. The archon must begin and end the teleport on squares that are touching earth or stone. When the archon is bloodied, this ability becomes usable at will.
____________
Minor Actions
-
Close burst Heavy Feet (once per round; at will):
Targets one or two enemies within 5; +13 vs. Fortitude; target is pulled 2 squares and slowed until the end of the archon’s next turn.
____________
Reactions
-
Sink Away (when the archon takes 20 damage or more from a single attack):
Recharge Earth Mastery and use it immediately.
____________
Alignment Chaotic Evil
Languages Primordial
Str 24 (+10) Con 26 (+11) Dex 10 (+3) Int 16 (+6) Wis 20 (+8) Cha 18 (+7)


Stone Archon Fleshmasher; Level 12 Elite Soldier (1,400 XP)
Medium elemental humanoid (earth)
____________
Initiative +8 Perception +11 (tremorsense 5)
HP 208; Bloodied 104
AC 30 Fortitude 28 Reflex 22 Will 26
Speed 5
Skills +14 Religion
Saving Throws +2
Action Points 1
____________
Passive
-
aura Battlefield Awareness aura 1; enemies within the aura are marked by the archon.
-
Combat Superiority
If the archon hits with an opportunity attack provoked by movement, the enemy stops moving.
____________
Standard Actions
-
basic melee attack Flail (at will):
+19 vs. AC; 3d6+5 damage; if the target is slowed, it is now immobilized until the end of the fleshmasher’s next turn. If a creature is killed by this attack, its body turns to stone.
-
melee Swishing Flail (at will):
Make two flail attacks against different targets.
____________
Minor Actions
-
Close burst Heavy Feet (once per round; at will):
Targets one or two enemies within 5; +17 vs. Fortitude; target is slowed until the end of the archon’s next turn.
____________
Reactions
-
Sink Away (when the archon takes 20 damage or more from a single attack):
Teleport three squares and make a basic attack. The archon must begin and end the teleport on squares that are touching earth or stone.
____________
Alignment Chaotic Evil
Languages Primordial
Str 24 (+13) Con 26 (+14) Dex 10 (+6) Int 16 (+9) Wis 20 (+11) Cha 18 (+10)


Stone Archon Fleshmasher; Level 16 Soldier (1,400 XP)
Medium elemental humanoid (earth)
____________
Initiative +10 Perception +13 (tremorsense 5)
HP 128; Bloodied 64
AC 32 Fortitude 30 Reflex 26 Will 28
Speed 5
Skills +16 Religion
____________
Standard Actions
-
basic melee attack Flail (at will):
+21 vs. AC; 3d8+7 damage; if the target is slowed, it is now immobilized until the end of the fleshmasher’s next turn. If a creature is killed by this attack, its body turns to stone.
____________
Minor Actions
-
Close burst Heavy Feet (once per round; at will):
Targets one enemy within 5; +19 vs. Fortitude; target is slowed until the end of the archon’s next turn.
____________
Reactions
-
Sink Away (when the archon takes 25 damage or more from a single attack):
Teleport three squares and make a basic attack. The archon must begin and end the teleport on squares that are touching earth or stone.
____________
Alignment Chaotic Evil
Languages Primordial
Str 24 (+15) Con 26 (+16) Dex 10 (+8) Int 16 (+11) Wis 20 (+13) Cha 18 (+12)


Stone Archon Fleshmasher; Level 20 Lesser Soldier (1,400 XP)
Medium elemental humanoid (earth)
____________
Initiative +12 Perception +15 (tremorsense 5)
HP 76
AC 36 Fortitude 34 Reflex 31 Will 32
Speed 5
Skills +18 Religion
Saving Throws A lesser monster automatically fails all saving throws.
____________
Standard Actions
-
basic melee attack Flail (at will):
+25 vs. AC; 18 damage and the target is slowed until the end of the archon‘s next turn; if it was already slowed it is now immobilized until the end of the fleshmasher’s next turn. If a creature is killed by this attack, its body turns to stone.
____________
Reactions
-
Sink Away (when the archon takes 35 damage or more from a single attack):
Teleport three squares. The archon must begin and end the teleport on squares that are touching earth or stone.
____________
Alignment Chaotic Evil
Languages Primordial
Str 24 (+17) Con 26 (+18) Dex 10 (+10) Int 16 (+13) Wis 20 (+15) Cha 18 (+14)


Stone Archon Fleshmasher; Level 24 Minion Soldier (1,400 XP)
Medium elemental humanoid (earth)
____________
Initiative +14 Perception +17 (tremorsense 5)
HP 1 (a minion is never damaged by an attack that misses)
AC 40 Fortitude 38 Reflex 34 Will 36
Speed 5
Skills +20 Religion
____________
Standard Actions
-
basic melee attack Flail (at will):
+29 vs. AC; 15 damage and the target is slowed until the end of the archon‘s next turn; if it was already slowed it is now immobilized until the end of the fleshmasher’s next turn. If a creature is killed by this attack, its body turns to stone.
____________
Alignment Chaotic Evil
Languages Primordial
Str 24 (+19) Con 26 (+20) Dex 10 (+12) Int 16 (+15) Wis 20 (+17) Cha 18 (+16)

Monday, April 18, 2011

Lesser Monsters

Currently, there's a noticable gap in the spectrum of monster class; while we have a smooth progression of normal to elite to solo, there's a huge difference between a normal monster and a minion. What about monsters that - while weaker and more numerous than a standard opponent - aren't wimpy enough to be one-hit-kills? To use a Legend of Zelda comparison, DnD currently has miniblins, moblins, and bigblins, but we don't have any bokoblins. And killing bokoblins is fun. A super-minion, or "elite" minion, would fill the hole and allow for a bigger range of encounter packs.
Here is my take on a super-minion. Lesser monsters are worth half as much encounter space as a normal monster of their level, and are individually expected to cause half as much grief to the PC's.


Creating a Lesser Monster

A lesser monster is just like any other monster of its level and role, aside from the following:
  • It has one half as many hit points as a normal monster of its level and role.
  • It automatically fails all saving throws.
  • It is instantly killed by a critical hit.
  • Its attacks deal a set amount of damage, like a minion.
  • Defeating the creature awards only half as much XP as a normal monster of its level.

Lesser monsters are easily defeated by attacks that deal debilhitating, save-ends effects, and, unlike minions, they can take damage from attacks that miss. This means that they are vulnerable to every weapon and perk at a PC's disposal, allowing the players to have fun using their different powers against lesser monsters. At the same time, the lesser monster is hardy enough to take a few conventional attacks before dropping, and it can do a fair amount of damage, keeping a pair of them a serious threat.


Guidelines to Building Lesser Monsters

To make a lesser monster effective, keep the following in mind:
  • Lesser monsters deal a set amount of damage with each attack, but that amount should be slightly higher than what a minion does. If a first level minion brute deals 7 damage with an attack, a first level lesser brute should deal 9 or 10.
  • Lesser monsters should have one or more encounter or recharge powers, to further differentiate them from minions.
  • Lesser monsters are never bloodied. Avoid the temptation to give them abilities that take effect after they've been injured; that goes against the grain of their design, and the PC's will likely never get to see that ability used for more than a single round anyway.
  • A lesser monster's vulnerability to saving throws can make the PC wizard feel really badass when he throws his sleep spell, which is a good thing. However, keep in mind that a party with lots of save-or-die attacks at their disposal are going to cleave through lesser monsters much more easily than another party might, so plan encounters accordingly.
  • Lesser monsters should not typically have Leader or healing abilities. Like minions, they should have abilities that are conducive to teamwork.

For an example of a lesser monster, I took the Rylkar Tormenter from an earlier post and adapted it into a Lesser. I may go back and make this the "official" version, as I really did envision the Tormentor as being something that gangs up on its enemies, though not to the same extent of their Forager minions.


Rylkar Tormenter 
Level 1 Lesser Controller (XP: 50)
Tiny natural beast
Initiative: +3 Perception: +7 (darkvision)
Hit Points: 13
AC: 15 Fortitude: 13 Reflex: 14 Will: 13
Speed: 8
Resist: 5 disease

Vulnerable: a lesser monster is reduced to 0 hp if it sustains a critical hit.
Saving Throws: a lesser monster automatically fails all saving throws.
______________
Standard Actions
-  
Melee basic Bite (at will); +6 vs. AC; 8 normal and disease damage and use Attach.
______________
Passive
-
Attach; after biting someone, the Tormenter digs its teeth into their flesh and refuses to let go, entering the target´s square. While attached, the Tormenter cannot be targeted by opportunity attacks, and recieves a +4 bonus to its AC, Fortitude, and Reflex defenses. Attacks against the rylkar that target any of these defenses that miss will instead hit the creature to which it is attached. The rylkar gains a +2 bonus to attack rolls against its victim, but cannot attack anyone else until it lets go. The rylkar´s victim is slowed. Save ends; on a succesful saving throw, the Tormenter reappears in a space adjacent to the target. 
-
Scurry; the rylkar can move through occupied squares as long as it begins and ends its move in empty ones.
______________
Strength: 8 Constitution: 14 Dexterity: 16 Intelligence: 6 Wisdom: 14 Charisma: 10
Alignment: Evil Languages: None (understands Deep Speech)



With only a few, very easy stat changes, the tormentor has become the monster I really wanted it to be. 

In future monster posts, I will stat creatures that were designed from the ground up to be Lesser monsters, with abilities that play into working in groups of two. I will also, in the near future, be posting a more in-depth discussion of how to use different monster classes, and some guidelines for "upgrading" or "downgrading" monsters from one class to another.

Saturday, March 5, 2011

Skill Challenges in Combat Encounters

Some time ago, a clever individual on the Wizards of the Coast forum posted an intriguing idea of his about working skill challenges into monster statblocks. Unfortunately, I don't recall this fellow's name, but I have used his homebrew mechanics to great effect in my games, and I'd like you to be able to do the same.


The Fluff

The concept here is that rather than simply bludgeoning a monster to death by lowering its hit points, your heroes can sabotage their enemy through more clever means. Imagine cutting the ropes holding the palanquin on an elephant's back, so that the archers mounted on the beast fall to the ground. Or the party's magic users working complex spells to bring the incorporeal demon into the physical world so that the fighter can harm it with his sword. These escapades don't directly injure the enemy, but they prevent it from using its more dangerous abilities and makes the battle much easier for the PC's.


The Crunch

The DM describes the monster in such a way that the PC's are likely to notice a specific weakness (alternatively, the DM can inform the players directly of the weakness if they roll high enough on their Knowledge checks to identify the creature). To take advantage of that weakness, the party shares a skill challenge in the heat of combat. In general, you'll want to assign average to hard DC's for the skill checks. Using one of the Primary skills for the challenge is a Standard Action. Using a Secondary skill is a Minor or Free Action (depending on the skill in question. Its the DM's call). If the skill challenge succeeds, the monster will be prevented from using some of its abilities for the rest of the battle, and might take other penalties or hit point damage as well. If the skill challenge fails, the PC's will have wasted a bunch of actions in the heat of battle.


An Example

The PC's are in the savanna on a dark, moonless night, surrounded by a pack of vicious gnolls. The filthy beasts growl and wave their weapons as they advance from beneath the tall grasses, looking frequently at the largest member of the pack for instructions, waiting for her cue to strike.

One of the PC's rolls a History check to see what he knows about gnolls. He gets a 26, which beats the DC 25 check to learn about their secret weakness. The DM tells the player - in addition to everything the Monster Manual says a roll of 26 should teach him about the creatures - that gnoll packs are led by the alpha female, who rules through intimidation and dominance displays; making the alpha appear weak or ridiculous might wreak havoc on their animalistic morale.

The primary skills for this challenge are Intimidate, Bluff, and Acrobatics. Secondary skills are Insight and Nature. The skill challenge has a complexity of 1 (four successes before two failures needed to pass the challenge) and a DC of 20.

The Warden acts first. He marches up to the alpha gnoll and, waving his enormous hammer over his head, he howls in primal fury (Intimidate). The Warden's player rolls a 21 on his Intimidate check; just high enough to make the gnoll forget herself and flinch in fear from his feint. The other gnolls see this as a sign of weakness. That's one success. Unfortunately, that was also his standard action for the round.

Next is the Rogue. He looks at the mildly cowed gnoll and makes an Insight check to see where she could best be attacked from next. He rolls a 23, which allows him to see that the alpha gnoll is off-balance from the Warden's intimidation. He turns to the Monk and tells her this, costing himself a minor action but giving the Monk a +2 bonus to her next skill check.

Its the gnolls' turn now. They close into melee and begin slashing at the heroes with their crude spears and axes. The fighter is flanked, preventing him from getting close to the alpha female...but the monk is not. She darts over to the alpha female and makes an Acrobatics check to confuse the beast with her movements. She rolls a 25; the alpha gnoll tries to slash at her, but is thrown off completely, and ends up banging the handle of her spear against her own paw and yelping in pain. A couple of the other gnolls appear to be chuckling in their hyena-like way.

Its the alpha gnoll's turn next. She attacks the Monk and does some nasty damage. She also uses some of her remaining dignity to give forth a deep howl, the sound of which whips her minions into a frenzy. The PC's need to break up the gnoll pecking order quickly, or this could get deadly.

Next is the Wizard. After casting an area spell to clear the attacking gnolls away from him, his player asks the DM if he can use Arcana to humiliate the alpha. The DM is taken aback, but decides "sure, why not?" The DC for this is going to be higher (25), though, since this is an unlikely skill for the situation. The Wizard spends an Action Point so he can take another Standard Action and tries to use an illusion to make the alpha gnoll appear to be wearing a dressing gown and wig. Against everyone's expectations, his player rolls a natural 20, for a total skill check of 32. The alpha gnoll seems to be wearing foppish formalwear, and the other gnolls are finding her harder to take seriously.

On the next turn, the Warden starts by trying to Intimidate the alpha gnoll again. This time, he only gets a 16, which isn't enough to faze her. He's wasted his standard action screaming and stamping his feet, and needs to spend his Action Point to flank the alpha gnoll and attack her with his hammer.

The Rogue slinks away from the gnoll attacking him (soaking up an opportunity attack in the process) and makes an Acrobatics check as he charges the alpha. He rolls a 22, and manages to make her trip over her own feet and fall facefirst in the mud, getting the muck all over her illusory gown. Four Successes, only one Failure. The gnolls can no longer respect their leader; they all suffer a -2 morale penalty to attack rolls for the rest of the encounter, and the alpha can no longer use her Howl and other leadership abilities. The fight is now a piece of cake for the PC's.


Guidelines

-The skill challenge should be appropriate to the type of monster and the battle conditions. A skill challenge using Arcana and Religion could prevent a mummy from using its Fear and Mummy Rot powers. A skill challenge using Athletics and Dungeoneering could cut off a hobgoblin soldier's full plate and drop his AC into the low teens. 

-The skill challenge should have average or hard DC's and a complexity of 1. The idea is that it should be no easier or harder than hitting the monster with conventional attacks.

-Only Elite and Solo monsters should come with skill challenges (normal monsters aren't worth the trouble).

-The PC's should be able to learn about the skill challenge by listening to the DM's description of the monster, or by rolling a high DC on their Knowledge checks to identify the creature. Ideally, both methods of learning about the challenge should be available.

-You should include enough different skills for every party member to be able to contribute. You should also make sure that succeeding on the skill challenge is worth all those actions; make the monster pay dearly for their success.

-To use some skills, the PC must be adjacent to the monster. To use others, there should be a maximum distance of 5 or 10 squares. Use your judgment.

-The skill challenge can only be attempted once.


Variations

-Using a Primary skill only requires a minor action, but failure provokes an Opportunity Attack from the monster.

-Instead of penalizing the monster, succeeding at the skill challenge inflicts a massive amount of damage on it. For instance, climbing onto a dragon's back and stabbing it in the head (Athletics, Acrobatics, and Bluff checks required) might cause the beast to lose one quarter of its maximum hit points.

-The skill challenge can be attempted multiple times, but the DC's increase each time.

-Failing the skill challenge makes the monster stronger or heals it.

-Normal, non-elite or solo monsters can have skill challenges associated with them. Beating the skill challenge kills the monster outright.