Design Unique Monsters in Minutes: The OSWR Method
I’m going to show you how I create unique, interesting monsters in minutes. Not stat blocks. Actual creatures with personality that’ll challenge your players.
The Core Principle
In Olde Swords Reign, a monster’s hit die tells you almost everything:
- To-hit bonus = Hit die (2 HD = +2 to hit)
- Saves: 0-4 HD = Easy (DC 8), 5-8 HD = Normal (DC 12), 9+ HD = Hard (DC 16)
- Proficiency: 0-4 = +2, 5-8 = +3, 9-12 = +4
- Hit points = (4 + CON modifier) × Hit Die
For armour, I use player armour as a guide. Leather skin? AC 12 + DEX. Solid shell? Use the chain or plate equivalent.
The Three-Line Monster
I borrowed this from an RPG zine I love. Each monster gets:
- A description - What players see
- A unique tactic or behaviour - What makes it interesting
- A special ability - Something that changes how combat plays
That’s it. Three lines gives you more character than a page of stats.
Let’s Build Something: Funglins
I wanted fungal goblins. Here’s how fast this goes:
Spore Funglin
| 1/2 HD | AC 12 | HP 3 | Claw 1d4 |
Small bloated goblin, creepy smile, palms open
Walks toward PCs saying “we want to be friends.” When within 5 feet, explodes in 15-foot radius. Easy save or take 1d6 damage. Also explodes if killed.
That’s your suicide bomber. Terrifying in groups. Players will hear “we want to be friends” and panic.
Shield Funglin
| 1 HD | AC 14 | HP 5 | Sharp stick 1d6 |
Large shield-spore growing from arm
Can sacrifice shield to negate one attack completely. Can take damage for any adjacent Spore Funglin.
Now your suicide bombers have bodyguards. Players have to figure out how to get past the shields to stop the exploders.
Rage Funglin
| 2 HD | AC 14 | HP 12 | Claws 1d6 |
Red-eyed, dribbling, carries small spore bag
Spore bag (3 uses): Sniff to gain 2 attacks for 1d4 rounds.
For players who loot it: Same effect, but when spores run out, -1d6 to all checks until a breather. They can’t recover HP during that breather either. Risk vs reward.
Funglin Mother
| 5 HD | AC 10 | HP 35 | Saves: Normal (physical and mental) |
Huge fungal mass with several tiny goblin heads
- Can release spore cloud to everything within 5 feet
- Can throw spore sacs at range
- Directs other funglins intelligently
Her spores (roll d6):
- 1-2: Attack nearest PC
- 3-4: Heal a downed funglin (breather effect)
- 5-6: Return to mother and heal her
She’s stuck to the wall but she’s smart. INT +3, WIS +1, CHA +2. She can talk, bargain, manipulate. This isn’t just a boss fight - she’s the centre of a mini-campaign.
The Result
Four unique monsters, created in about 20 minutes while explaining the process. Each one presents different tactical challenges:
- Spore Funglins - Can’t let them close
- Shield Funglins - Protecting the exploders
- Rage Funglins - Carrying loot worth stealing, hitting hard
- Mother - The puppeteer making them all work together
This could be a cave complex near a starting town. Too hard at first - players run. As they level, the fungal influence spreads to town. NPCs get infected. The threat grows.
The Method
- Start with a hit die
- Add stats that make sense for the creature
- Calculate HP and AC from those stats
- Write one line of description
- Add one tactic or behaviour
- Add one special ability
Done. A unique monster that’ll give your players actual decisions to make, not just a bag of hit points to deplete.
Get the full rules. Olde Swords Reign