General Appearance
A sturdy, symmetrically built working terrier like the Sealyhams of old. There should be a combination of substance, power, balance and hard muscular condition. Any tendency to grossness or weediness is a serious fault.

Characteristics
A friendly dog with no aggressive tendencies towards people or other dogs, though a dog with an overly soft temperament is as undesirable as a fearful or nervous dog.

Head
In balance with other proportions of the dog, and in keeping with its general conformation. Skull - broad, only slightly curved between the ears, flattening to a slight but definite stop. Foreface - broad and well filled under the eye with a medium length, deep muzzle. Cheeks - muscular, but not coarse or prominent. Nose - black irrespective of the color of the dog. Nose - black irrespective of the color of the dog. Jaw - strong, deep and well developed. Lips - tight and clean. Teeth- Sound and regularly placed, gripping with a scissor-like action, the lower incisors close behind and just touching the upper. Not to be overshot or undershot. Eyes - dark, almond shaped eyes, neither prominent nor sunken, with well-pigmented eye rims. Ears - moderate in size, preferably small, v-shaped and carried close to the head. Prick or flyaway ears are undesirable.

Neck
Strong, muscular and of medium length broadening to blend into the body and free from throatiness.

Forequarters
The shoulders are broad of blade, sloping, muscular and well angulated to the upper arm and at the point of the withers should not be too closely set. The forelegs have strong, round bone, extending to the feet without weakness of the pasterns. The forelegs should be perfectly straight when viewed from the front.

Hindquarters
Broad, strong and muscular. Thighs are long, broad and well let down. When viewed from behind the hind legs, from the hocks to the feet, are straight and placed neither close nor too wide apart.

Body
The length of the body from the point of the breastbone in a straight line to the buttocks is slightly greater than the height at the withers. The top line is level, back strong, with ribs well sprung and ribbed back (not barrel ribbed). The chest is deep and muscular and moderately broad, loins are broad, deep and muscular with deep flanks strongly coupled between the fore and hindquarters.

Tail
The set of tail is neither high nor low set. Either docked or undocked tails are acceptable

Coat
Fairly harsh, weather resistant and of medium length. Very soft, fluffy coats are undesirable but short, harsh Norfolk type coats are acceptable.

Color

• Frost:  Tan, all shades. Named in honor of the late Jumbo Frost.
• Irwin:  A white base coat of with colored markings in a piebald or extreme white spotted pattern. Markings may be tan (all shades), black, badger-gray, black and tan or badger-gray and tan. A completely white dog is also acceptable. Named in honor of Jane Irwin one of the founders of the British Club who preferred this color combination.
• Black & Tan or Saddle & Tan (the saddle can be black or bluish gray) or black and tan dog. *(Name pending re Boards Approval.)
• Goodspice:  A rare, all black dog with or without markings. Sometimes they turn steel gray or almost a "blue" color. Named in honor of terrier expert Margery Good of  Goodspice Kennels who recognized just how rare and precious these dogs were and had the courage to stand up and fight for them. *(Name pending re Boards Approval.)

Please Note: All colors (and all color combination) of Lucas Terriers are valued equally in the United States. This is a change from the British Standard as of 2011.

 
Height at withers
Dogs 10 - 12 inches
Females - 11 inches

Weight
Dogs 14 - 20 lbs
Females - 17 lbs

Movement
Soundness is of paramount importance. The action is true, free and supple. Capability of quick and sudden movement is essential. Stiltedness, loaded or slack shoulders, straight shoulder placement, weakness at elbows, pasterns or feet, straight stifles, cow or bow hocks must be regarded as serious faults.