Help a newbie DM for a fair challenge

[~Mozza]

Hi all, in a couple of week I'll be a DM for a session in a sandbox campagin in the Darkmoon Vale on Golarion. I'm no expert at DMing, and I find problems in putting some fun and most of all, fair battles. There will be 3 battles at minimum, one is the boss and it's really good as it is, but I ask for some help on the first two.

First of all, the party: not so optimized, 5-man lvl6 party
1) pyrocinetic: lots of hp, good blasting potential, ranged
2) cleric of sarenrae: good AC, bit more optimized, use ranged spells and sword
3) gunslinger-ranger: homeruled class, not so powerful at all, ranged
4) slayer: basically the only one melee, fights well only when flanking
5) the current DM oneshot PC, don't know what it is

The first battle will be a random encounter: what CR will be optimal?
I thought of two or three CR 7 creature or one powerful CR 9. Based on what's best I'll decide what monster I'll be using

The second is a monk 1 / martial artist X NPC: a samurai with a katana that uses a combination of flurry of blows katana/unarmed strike that will not fight to the death or to the death of the PCs.
What level is adequate?

Thanks all for the time spent reading, and maybe answering :)

[Geddy2112]

As a rule of thumb, you generally want several weaker enemies vs one strong one. A strong single enemy is either overwhelmed easily by the party through action economy, or is so powerful they simply annihilate the party. A single monster gets one turn, but your party has 5-throwing straight dice the party usually wins, but this is before they buff or do other things that benefit them exponentially vs the monster's linear scaling. Single monsters are also far more vulnerable to a save or lose/save or die. Your cleric needs to land just one of these and the encounter is over.

Against a party of 5 6th level PC's 3 CR7 level enemies is probably fine, although CR is not the best system-some monsters are way over or under. That Damned Crab is a CR 3 that could be far more powerful than a 4person 3rd level party.

For your boss, even low level mooks/meatshields help. Throw in a few of the monk's apprentices, or maybe some wild animals that they tamed to fight with them. Another option is favorable conditions for your enemy and unfavorable for the PC's. Dense fog when they have blindsight, for example. As far as level, anything about 4+ levels or CR over is generally a lethal encounter for a party, where anything 4 levels or CR lower than the party is trivial. Shoot for a level 8 with some low level friends, maybe a 9 if the friends are just pitchfork carrying commoners.

[ArtAndor]

Good day to you.

Speaking from my experience, most of my players do not enjoy "Fair Challenge". They look for a good story to tell and vivid experience of adrenaline and tension. When we started our campaigns, I did introduce random encounters which quickly bore them as they normally lasted so long it became a chore. So I halved their hp and monster hp, no the fights are fast paced and bring adrenaline they wanted. Next I put in several enviromental things as Geddy mensioned. Rain to make ranged weapons worse and ground slippery for combat, High winds to unbalance, even Night Time made for an excellent fight with two earth elementals where the players were forced to be creative with their sources of light to see their targets.

If it is your first time DM'ing. I would suggest your first fight to be 2 random CR 5 and 1 random CR7. Mostly for the sake of variation and allowing you to try and use some nifty tactics against them. There is only one melee? Well, he is now stuck with one cr 6 as the others are running after the squishier ones. It will force your players to think and try to gain every advantage from enviroment that they can get. For instance - Blaster could drop nearby wall/tree to block the passage and buy them some time.

Thinking "What would be cool and how will it challenge my players" is the way to go when designing memorable encounters.

An example of a good quick fight using monster advancer. I use this one (http://www.monsteradvancer.com/) for sheer diversity

A couple of CR 5 spiders would make an excellent fight. Tunnels make it hard for people to fight and web will make it hard to move, making the already nimble spider a very dangerous oponent. They bite, run away and cannot be cought fast enough due to web. Players can always burn the web, but it fills the area with smoke. They can move as much as they want now, but they are now covered in fog. The spiders have tremorsense so they are still at advantage. Ridding the tunnel of smoke or waiting long enough for it to go away would strip spiders of all advantages... Or cleric could simply summon his/her own spiders and buff them?.. They could simply make a trap for spiders by tying a few alchemical flasks to a rope. Charm monster, wild empathy... Plenty of creative solutions possible to a creative, vivid and exciting encounter. I strongly encourage DM's I know to think of battles as a tension rising narrative, rather than "A fair challenge".

On a Sidenote: If your players want it to be a tabletop WoW-esque gameplay, rather than narrative roleplay, it becomes another story.

Hope this helps!

Edit: Forgot to put the link for the random generator yesterday.

[Selion]

I agree with everything, as a DM at the beginning i failed to give good fights to my group exactly for this reason: i wanted the Big Bad Boss alone. One day i had the party assaulted by a triceratops tamed by drows, they had a wooden platform on the beast and used poisonous crossbows. This gave the party hell, despite being just a +1 CR encounter.

In this situation i would use a Lev 7 samurai with four Lev 3 ninjas (CR 8-9 depending on gear).
Ninjas should use smokescreens to ambush the party and use hit and run strategy. They should not have troubles finding a way to flank their enemies with acrobatic checks, give all of them the teamwork feat "outflank" for a nice +4 ad keep one of them at distance using poisonous arrows (blue whinnis is a cheap and effective poison).
All of that should offer a nice diversion while your samurai slices the PCs one by one