If you play a roleplaying game regularly, it's only a matter of time before your players become familiar with the monsters they are likely to meet. It's not a totally bad thing; if your adventurers are staying in the same kind of area it is only logical that they will get to know the local critters and their abilities, strengths and weaknesses.
But I believe the game loses some of its mystery if you bring an opponent in, and you can see your players bringing their stat block up in their minds. For the group I play in, it is even more of a challenge because we have a player with a nearly eidetic memory - he's pretty good about playing it straight, and is a wonderful DM-helper when it comes to rules queries.
A solution I adopt quite frequently is to modify monsters. This can vary from the most minor of changes to their "fluff" just so that players don't immediately know what they are facing, to major adjustments which can utterly change a beast beyond all recognition.
I have listed below a few of the techniques I use. It's mainly from a Dungeons & Dragons perspective (because that is mostly what I play), but the principles can be applied to pretty much any RPG system. One thing I should mention is that the list below isn't an either/or menu, it works really well to use two or three techniques together to turn an opponent from something familiar into something almost impossible to deconstruct.
Reskins
This is a simple process of changing the appearance of a creature to a greater or lesser extent. Think of it as a kind of "camouflage"; the stat block stays pretty much the same, but by describing an opponent differently it throws the players off just enough to keep things fresh.
Examples include a minotaur with a goat's head, or changing the wasps in a swarm of insects to bees even though the effects are unchanged.
Changed Environments
Moving a monster into a different environment is more than just plonking it down somewhere different, if you think it through it can significantly change things.
Think about the impact on resistances and vulnerabilities; turning a salamander into a cold-environment creature will mean it does cold instead of heat-based damage (potentially messing with the resistances the characters may have set up for themselves), and may be resistant to cold-type attacks instead of fire ones.
Movement and behaviour may also change. In my homebrew world, I had a species of blue whale which lived in arctic snowfields. Their fins had strengthened and become more rigid so they acts like skis, but left deep trenches behind which would be buried by fresh snow to become a dangerous hidden obstacle. The ice-whales fed on any algae and other food particles in the ice, sliding along quite fast and creating a serious risk to characters who might get accidentally overrun and crushed even though the whales weren't aggressive or hostile. The ice-orcas which preyed on the whales, on the other hand, took aggression and hostility to an extreme, and were incredibly dangerous opponents.
Buffs and Nerfs
Buffing or nerfing monsters to match character level or ability is something I think of as essential.
Sometimes it can be simple upgrades of stat-blocks; giving the monsters more hit points or better armour and weapons. At other times, I'll swap in a stat block from a related but more dangerous monster, for example using orc or bugbear stats to create tougher than normal goblins (although usually with the original creature's abilities).
At other times, I might do a bit of extra work to more completely customise a buff or nerf. I'll look in particular at how many attacks they have, how easily they can hit and how much damage they can dish out (e.g. if they are stronger, will they add a strength bonus to their attack and damage rolls). I'll also look at saving throws, and adjust them up or down just to make sure that spellcasters will feel the impact of the changes as well.
Special Abilities
This is a customisation I have great fun with, and as long as I am consistent I don't feel obliged to totally stick to the rules. It is an area where the storyline comes to the fore. I ask myself questions about how the monsters fit into the adventure, and whether the theme of the adventure should be reflected in the monsters' abilities. Sometimes I'll just pull abilities across from another monster (e.g. giving a goblin troll-like regeneration properties), and at other times I might invent something completely new.
Examples of this might include giving subterranean creatures the ability to blend into stone cavern walls as a form of concealment, or even to have a limited ability to travel through rock. Or giving an otherwise ordinary creature some kind of breath weapon, poisonous touch, or spell-like ability. At an extreme end of the spectrum is giving the creatures legendary and/or lair actions (for those who don't play Dungeons & Dragons, these are ways to give particularly powerful monsters extra abilities which can be used to interrupt other characters' turns or create environmental effects in their lairs).
Tribes and Superheroes
A key way to upgrade and customise monsters is to give them a social structure, play them intelligently, and give them leaders.
In Dungeons and Dragons, a good example is hobgoblins. They have a martial society, and I completely messed up a mid-level party by having the hobgoblins act as a pike block, with archers and spellcasters in the centre protected by them. They had observed the party using scouts and whittled away the area-effect spells the party's spellcasters had. The hobgoblins also had sergeants and officers, who I buffed quite significantly to make them really tough opponents. The first clue the party had that things were going to be tough was when the archers (acting intelligently) targeted the charging paladin's warhorse, who wasn't as well armoured as the tin can riding it.
Having monsters led by upgraded heroes of their own type (or mercenaries of another type, e.g. kobolds hiring some ogre bodyguards) can create some very challenging encounters, although as a DM you should try to build in some mechanisms you can apply if it looks like the party have gone into a death spiral.
Monsters With Character Qualities
Probably the toughest way you can customise monsters is to treat them like player characters. However, it also makes them the hardest to run, so it's best to only do this with one or two monsters within a larger encounter.
In D&D, the mechanic for this is to give monsters additional character levels. So, for example, I recently created an NPC called Lady Rannath as the Big Bad. She's a Frost Gaint wizard, so I started with Frost Giant stat block. The party were attacking her in her lair, which gave her a couple of lair actions. In addition, as a powerful wizard, I gave her nine levels of wizard on top of her Frost Giant stats. Plus some magic items and a good number of pre-prepared scrolls and potions. It was quite a lot of work creating her - I effectively took the base block and "levelled up" nine times, but the end result was well worth the effort.
With any monster like this, balancing the action economy is essential, otherwise your carefully crafted final boss will get steamrollered as the characters have ten times as many actions per round as your monster. In this case, I gave Lady Rannath a variety of minions to tie the party up and keep them busy while she levitated and used invisibility to rain spells down on the characters. It all made for a suitably epic final battle to end the adventure on.
Image by press 👍 and ⭐ from Pixabay
So what do you think ? What other ways do you use to adapt your monsters and keep things fresh and interesting for your players ?
