Mastiff 5e: Stats, Guard Dogs and Mounts for Small Characters

A mastiff is a CR 1/8 Medium Beast with AC 12, 5 hit points, a 40-foot speed and one attack: a bite for 4 damage that knocks the target Prone. In the 2014 rules the target gets a DC 11 Strength save against the knockdown. In the 2024 rules there's no save: any Medium or smaller creature it bites hits the floor. The 2014 SRD describes mastiffs as loyal hounds trained as guard, hunting and war dogs, and says halflings and other Small humanoids ride them. So this page covers two things: the dog the guards bring, and the mount a Small character can use.

Table of Contents

• •Mastiff Stat Block (2014)
• •The Mastiff in the 2024 Rules
• •How Mastiffs Fight
• •Riding a Mastiff
• •Running a Mastiff Encounter
• •How Players Beat Mastiffs
• •Mastiff Encounter Ideas
• •Frequently Asked Questions

Mastiff Stat Block (2014)

The SRD 5.1 mastiff:

Keen Hearing and Smell is the guard-dog trait. It gives Advantage on Perception checks that use hearing or smell, and a passive check with Advantage adds 5. So the mastiff's passive Perception is 13 for spotting, but 18 for hearing a footstep or smelling a stranger. A character sneaking past needs a Stealth total of 18 or more.

In the SRD 5.1 equipment lists a mastiff costs 25 gp, moves 40 feet and has a carrying capacity of 195 pounds. The 2024 list keeps the 25 GP price and 195 lb. capacity.

The Mastiff in the 2024 Rules

SRD 5.2.1 keeps the mastiff's AC, hit points, speed, CR and price, and changes how it notices and how it bites.

The 2024 bite is the big change. Every hit on a human, elf, dwarf, halfling or other Medium or Small creature is an automatic knockdown, but a Large creature (an ogre, a horse) stays up. The 2024 dog also sees in the dark, while losing the "Advantage on hearing and smell" trait: its passive Perception is a flat 15, lower than the 2014 dog's 18 for sound and scent.

How Mastiffs Fight

The bite is weak; the knockdown is the point. A Prone creature has Disadvantage on its attacks, melee attacks against it from within 5 feet have Advantage, and standing up costs half its movement. The mastiff sets up whoever fights next to it.

Against a lone intruder. Against AC 14, a mastiff hits on an 11 (50%):

With two dogs on one target, a 2024 pair knocks them down about 75% of the time each round. A guard (AC 16, 11 hit points, a spear) then attacks the Prone target with Advantage.

Dogs first, guards second. Run the dogs ahead of their handlers: they close 40 feet, bite, and knock the intruder flat just as the guards arrive.

Bark, then fight. Have the first mastiff that notices someone bark (a DM ruling: no action needed) and let the guards come running.

Riding a Mastiff

Mounted combat requires a willing mount at least one size larger than its rider with a suitable anatomy. A Medium mastiff can carry a Small rider: a halfling, a gnome, a goblin. It can't carry a Medium character.

• •It's a real speed upgrade. At 40 feet the mastiff beats a Small character's walking speed (25 feet for a 2014 halfling or gnome, 30 in 2024), and a controlled mount can Dash for 80 feet.
• •Controlled or independent. A controlled mount (one trained to accept a rider) moves on your turn and can only Dash, Disengage or Dodge. It doesn't bite. If you want the dog to bite, let it act as an independent mount on its own initiative. The trade is control.
• •It's fragile. 5 hit points and AC 12. Any attack that targets the dog instead of you can kill it and leave you on foot. In both editions, if an effect moves your mount against its will, you make a DC 10 Dexterity save or fall off.

Find Steed (2014 only). In the 2014 SRD, a paladin's Find Steed can summon a warhorse, pony, camel, elk or mastiff. The mastiff steed becomes a Celestial, Fey or Fiend, its Intelligence rises to 6, and it understands one language you speak. Spells you cast on yourself can also target it while you ride. The 2024 Find Steed summons its own Otherworldly Steed stat block that looks like a Large animal, so the mastiff is no longer an option.

Other ways to get a dog. A Robe of Useful Items can have a patch that becomes 2 mastiffs, the rust Bag of Tricks produces a mastiff on a roll of 3, and the Onyx Dog figurine becomes a mastiff with Intelligence 8 that speaks Common (it sees invisible creatures within 60 feet in 2014 and has 60-foot Blindsight in 2024). A druid can also Wild Shape into a mastiff at level 2 in both editions: it's CR 1/8 with no fly or swim speed.

Running a Mastiff Encounter

A mastiff is worth 25 XP. The 2024 budget (SRD 5.2.1) for four level 1 characters is 200 (Low), 300 (Moderate) and 400 (High):

Under the 2014 Dungeon Master's Guide guidelines (used by our encounter calculator), four mastiffs are 100 XP × 2 = 200 adjusted, a Medium fight for four level 1 characters.

Dogs alone are a Low fight at best; they earn their keep alongside people. Besides the guard patrol, a hunting party with a pack of hounds chasing the party through a forest is a strong level 1 or 2 chase scene.

How Players Beat Mastiffs

• •Kill the dog, not the guard. At 5 hit points, almost any hit drops a mastiff, and removing it removes the knockdowns.
• •Feed it. Dogs can be bribed. Animal Friendship works in both editions (Intelligence 3 is under the 2014 limit of 4), and against a 2024 dog's Wis +3 it's harder than you'd think: a DC 13 save fails 45% of the time.
• •Stand up before you attack. Standing costs half your speed; attacking from the ground means Disadvantage.
• •Beat the nose (2014) or the eyes (2024). Sneaking past a 2014 mastiff means beating a passive 18 for anything it can hear or smell; stay downwind and silent, or mask your scent. A 2024 mastiff has darkvision, so darkness doesn't hide you, but its passive Perception is only 15.
• •Big creatures stay up. A Large creature (a druid in a bear form, a polymorphed ally) ignores the 2024 knockdown entirely.

Mastiff Encounter Ideas

The kennel master's debt. The local lord's kennel master breeds mastiffs and sells them to every manor in the county. He owes a dangerous man money, and that man wants a key to the lord's house. The kennel master's dogs know every guard by smell. The party can steal a dog, befriend one, or simply walk in with the kennel master on dog-delivery day.

The halfling courier. A halfling messenger on a mastiff is supposed to carry the party's urgent letter over the hills. Halfway there, her dog takes a crossbow bolt from someone who wants the letter stopped. The party finds the wounded dog, with no rider, still guarding the satchel from anyone who approaches.

The guardian's last order. A ruined manor still has its dogs: three mastiffs, half-wild now, who have kept intruders out since their master died. They attack anyone who enters the house but won't follow past the garden wall. A character who calms them learns that they have been guarding a door in the cellar.

Frequently Asked Questions

What CR is a mastiff in 5e?

A mastiff is CR 1/8 and worth 25 XP in both the 2014 and 2024 rules. It has AC 12 and 5 hit points in both.

Can a halfling ride a mastiff in 5e?

Yes. A mount must be at least one size larger than its rider, so a Medium mastiff can carry a Small character, and the 2014 SRD says halflings and other Small humanoids ride mastiffs. It costs 25 gp and carries 195 pounds, enough for a halfling in armor with a pack.

Can Find Steed summon a mastiff?

In the 2014 rules, yes: mastiff is one of the five listed steed forms. The 2024 Find Steed summons an Otherworldly Steed that looks like a Large animal, so a mastiff isn't an option.

Does a mastiff's bite knock you prone?

In 2014, a creature it bites must succeed on a DC 11 Strength save or be knocked Prone. In 2024, any Medium or smaller creature it hits is knocked Prone with no save.

What's the difference between a mastiff and a wolf?

A wolf is CR 1/4 with 11 hit points and Pack Tactics, Advantage on attacks when an ally is next to its target. A mastiff is CR 1/8 with 5 hit points, no Pack Tactics, and is trained to serve people. Wolves hunt the party; mastiffs guard against it. If the guard dogs become recurring NPCs, Loreify's session notes remember their names for you.

Stat blocks: System Reference Document 5.1 (2014) and 5.2.1 (2024), Wizards of the Coast, CC-BY-4.0. Tactics, encounter math and ideas are Loreify's own.