Lord Zardoz
Explorer
My own ideas
There are a large number of things you can do to your players with lower CR monsters that can make their lives miserable. The ones I will post here do not require adding HD or class levels.
Exploit Immunities:
If a creature is immune to a type of damage, then by all means exploit that immunity flagrantly. Undead are a good example. Skeletons are immune to cold. So if you create a room made of ice that inflicts cold damage every round, you can fill it with Skeletons, who will be unimpaired by this. In this kind of encounter, the monsters should do as much as they can to keep players in the room, rather then attack directly.
Pin Cushions:
Past a certain point, low HD monsters are better off using ranged weapons then they are going toe to toe. Attack, then move away, and repeat, but try not to exceed medium range. Use cover if you can to avoid counter archery. Also, make sure you focus your fire on the weakest link. The Atk bonus will already suck.
Non Standard Equipment:
There is not much that would prevent you from improving the gear of your typical bad guys. Upgrade the Armour as much as you can justify. Consider using a reach weapon instead of a regular weapon. You can create a door based choke point where once you go through the doorway, you are in a square threatened by 14 attackers. 5 immediately adjacent, and 11 using the reach weapons to attack from the 2nd row back. The guy entering the area does get +4 cover to his AC from the reach weapons, but who cares, you throwing an extra 11 attacks. Not all will miss. Also consider liberal use of poisoned weapons.
Difficult Terrain:
Low HD creatures do not lose as much in difficult terrain as higher level characters. The loss of a 5 foot step does not hurt so much, because you only had 1 attack anyway if your an Orc. But if your the 13th level Fighter, your losing the iterative attacks. If you have a reach weapon, the AoO cannot be avoided if someone moves adjacent. And if you attack at range, it takes them that much longer to reach you.
Tactical Traps: As someone else pointed out, a simple pit trap is one thing, but the same trap in a room with hostiles is an even bigger problem. Again, exploit immunities. Poison gas in a room full of zombies is just good news for the zombies.
Envelopment:
Whenever you can justify it, approach from more then one direction. It makes flanking easier, and it minimizes the chances of the encounter ending when someone says "I cast fireball".
Disease:
Consider making a point of using the disease rules more often, as opposed to only when a monster attack inflicts a disease. Ability damage from diseases scales better and is often more of a pain to get rid of then normal damage. And Orcs, Goblins, etc, are not exactly noted for their cleanliness.
And now some specific ideas.
Pit Trap of Watery Death:
Have a pit trap that is 10 feet deep, fulled with water, and a 50 pound steel grate that drops on top once someone falls in, settling just below the water. The poor bastard that falls in will have a few problems to deal with. First being that his feet do not touch the ground, so he cannot easily push the grate off the top. And since it is a grate, you can have monsters on top with spears to stab at him as he tries to lift the grate. Bonus points if you put some nasties in the pit with him to try to hold him under or otherwise attack him.
Troll Diving:
Even with regeneration, Trolls eventually reach a point where they no longer have the attack bonus to easily hit higher level PC's. But they still have a pretty good grapple check, and lots of strength. Bull rush the player off a cliff. Or, just grapple the player, then carry him to the edge of a cliff and jump. Trolls can heal from falling damage easily. Players not so much.
Poisoned Caltrops:
This is one of those ideas that you can read the heading and already know how its meant to work.
Mounted Archery:
As a harassment tactic, its perfect. Horses move fast, and you can shoot and move away as often as you need to, at least until you run out of arrows.
Strategic Withdrawl:
Combined with archery of some sort, this becomes very difficult to deal with. Engage your opponent, and get them to burn some buff spells. Then run away for about 10 mins, and return when the spells expire. Against players who use alot of Summon's and Buffs, this is very effective. Against Fireballs, not so much, what with the being too dead to run away. But as a rule, work out some criteria for when your low CR baddies will decide to bugger off. Running away when you have 20% losses is a workable hit and run tactic. Running away when your down to 20% of your initial forces means you waited a bit too long.
Support Tactics:
There are some very useful things you can do with the cannon fodder beyond simply attacking, or eating up a PC's attack. Setting up flanking attacks is obvious. Using Aid Another to improve attack rolls is also reasonably standard. But there are some other things you can also do. If the BBEG is good at using Disarm, a worthwhile tactic is to delay the cannon fodders action until after the BBEG. If the BBEG can disarm, then have the fodder pick up the disarmed weapon. If you can use magic items, then lay on some Cure spells from scrolls or wands onto your boss. If your boss gets his weapon disarmed or sundered, then give him yours. If the BBEG drops a player to 0 or less, then be a good little orc, and go for the Coup De Grace to finish him.
Be a Dick:
If the player dismounted to kill your boss, go steal or kill his horse. If there are hostages, have an Orc go and start killing them. If there are combustible objects in the room, set them on fire.
Prepared Cover Trap:
Have a static ambush location, with some archers set up behind a wooden barricde with spikes facing outward. Players like to charge into melee against archers. Have the space directly in front of the cover be a pit trap. When the guy who charged into melee falls in, roll / drop the cover in on top of him. If the pit was spiked, he should suffer 2d6 for falling in. He should suffer another 3d6 or so for having a 150 pound spiked object dropped on top of him, and will have difficulty getting out (Give it some arbitrary grapple check). Bonus points if you put poison on the spikes in the trap and on the cover.
That is all that comes to mind for now.
END COMMUNICATION
There are a large number of things you can do to your players with lower CR monsters that can make their lives miserable. The ones I will post here do not require adding HD or class levels.
Exploit Immunities:
If a creature is immune to a type of damage, then by all means exploit that immunity flagrantly. Undead are a good example. Skeletons are immune to cold. So if you create a room made of ice that inflicts cold damage every round, you can fill it with Skeletons, who will be unimpaired by this. In this kind of encounter, the monsters should do as much as they can to keep players in the room, rather then attack directly.
Pin Cushions:
Past a certain point, low HD monsters are better off using ranged weapons then they are going toe to toe. Attack, then move away, and repeat, but try not to exceed medium range. Use cover if you can to avoid counter archery. Also, make sure you focus your fire on the weakest link. The Atk bonus will already suck.
Non Standard Equipment:
There is not much that would prevent you from improving the gear of your typical bad guys. Upgrade the Armour as much as you can justify. Consider using a reach weapon instead of a regular weapon. You can create a door based choke point where once you go through the doorway, you are in a square threatened by 14 attackers. 5 immediately adjacent, and 11 using the reach weapons to attack from the 2nd row back. The guy entering the area does get +4 cover to his AC from the reach weapons, but who cares, you throwing an extra 11 attacks. Not all will miss. Also consider liberal use of poisoned weapons.
Difficult Terrain:
Low HD creatures do not lose as much in difficult terrain as higher level characters. The loss of a 5 foot step does not hurt so much, because you only had 1 attack anyway if your an Orc. But if your the 13th level Fighter, your losing the iterative attacks. If you have a reach weapon, the AoO cannot be avoided if someone moves adjacent. And if you attack at range, it takes them that much longer to reach you.
Tactical Traps: As someone else pointed out, a simple pit trap is one thing, but the same trap in a room with hostiles is an even bigger problem. Again, exploit immunities. Poison gas in a room full of zombies is just good news for the zombies.
Envelopment:
Whenever you can justify it, approach from more then one direction. It makes flanking easier, and it minimizes the chances of the encounter ending when someone says "I cast fireball".
Disease:
Consider making a point of using the disease rules more often, as opposed to only when a monster attack inflicts a disease. Ability damage from diseases scales better and is often more of a pain to get rid of then normal damage. And Orcs, Goblins, etc, are not exactly noted for their cleanliness.
And now some specific ideas.
Pit Trap of Watery Death:
Have a pit trap that is 10 feet deep, fulled with water, and a 50 pound steel grate that drops on top once someone falls in, settling just below the water. The poor bastard that falls in will have a few problems to deal with. First being that his feet do not touch the ground, so he cannot easily push the grate off the top. And since it is a grate, you can have monsters on top with spears to stab at him as he tries to lift the grate. Bonus points if you put some nasties in the pit with him to try to hold him under or otherwise attack him.
Troll Diving:
Even with regeneration, Trolls eventually reach a point where they no longer have the attack bonus to easily hit higher level PC's. But they still have a pretty good grapple check, and lots of strength. Bull rush the player off a cliff. Or, just grapple the player, then carry him to the edge of a cliff and jump. Trolls can heal from falling damage easily. Players not so much.
Poisoned Caltrops:
This is one of those ideas that you can read the heading and already know how its meant to work.
Mounted Archery:
As a harassment tactic, its perfect. Horses move fast, and you can shoot and move away as often as you need to, at least until you run out of arrows.
Strategic Withdrawl:
Combined with archery of some sort, this becomes very difficult to deal with. Engage your opponent, and get them to burn some buff spells. Then run away for about 10 mins, and return when the spells expire. Against players who use alot of Summon's and Buffs, this is very effective. Against Fireballs, not so much, what with the being too dead to run away. But as a rule, work out some criteria for when your low CR baddies will decide to bugger off. Running away when you have 20% losses is a workable hit and run tactic. Running away when your down to 20% of your initial forces means you waited a bit too long.
Support Tactics:
There are some very useful things you can do with the cannon fodder beyond simply attacking, or eating up a PC's attack. Setting up flanking attacks is obvious. Using Aid Another to improve attack rolls is also reasonably standard. But there are some other things you can also do. If the BBEG is good at using Disarm, a worthwhile tactic is to delay the cannon fodders action until after the BBEG. If the BBEG can disarm, then have the fodder pick up the disarmed weapon. If you can use magic items, then lay on some Cure spells from scrolls or wands onto your boss. If your boss gets his weapon disarmed or sundered, then give him yours. If the BBEG drops a player to 0 or less, then be a good little orc, and go for the Coup De Grace to finish him.
Be a Dick:
If the player dismounted to kill your boss, go steal or kill his horse. If there are hostages, have an Orc go and start killing them. If there are combustible objects in the room, set them on fire.
Prepared Cover Trap:
Have a static ambush location, with some archers set up behind a wooden barricde with spikes facing outward. Players like to charge into melee against archers. Have the space directly in front of the cover be a pit trap. When the guy who charged into melee falls in, roll / drop the cover in on top of him. If the pit was spiked, he should suffer 2d6 for falling in. He should suffer another 3d6 or so for having a 150 pound spiked object dropped on top of him, and will have difficulty getting out (Give it some arbitrary grapple check). Bonus points if you put poison on the spikes in the trap and on the cover.
That is all that comes to mind for now.
END COMMUNICATION
