Introduced in the pilot episode "The Gathering" (1992) as a young, quick-talking petty thief, his life changes when he realizes the existence of immortals, people born with an energy called the Quickening that makes them ageless and invincible to injury after they experience the shock of a violent death.

Richie meets Duncan MacLeod (Adrian Paul), an immortal born centuries ago in the Scottish Highlands.

He becomes an apprentice, friend and helper to Duncan and his mortal love Tessa Noël (Alexandra Vandernoot), often providing comic relief and youthful enthusiasm for their adventures.

Believing Richie simply needs guidance and support so he won't return to his criminal ways, Duncan and Tessa hire him to work in their shop and he joins them on several adventures.

While in Paris, MacLeod's friends are hunted by a group of people called Hunters, mortals who believe immortals are abominations who must be eliminated.

[4] MacLeod learns the Hunters are a rogue sub-group of a larger organization called the Watchers, mortals who have studied and recorded the lives of immortals for thousands of years.

Returning to Seacouver, Richie and Duncan befriend Joe Dawson, a benevolent Watcher assigned to observe the Highlander.

Tessa dies as Richie awakes, fully healed, realizing what MacLeod knew the night they first met: he is also immortal.

While saving the life of an ambassador, Richie inadvertently causes the death of a terrorist who is the friend of an Irish immortal named Annie Devlin.

Richie is determined to protect a woman he believes Mako is persecuting unfairly, but she later dies when she runs into the path of his truck.

Mako claims this was an accident and that he only sought to bring the woman to the authorities and Duncan pleads for Richie to listen to reason.

Duncan, believing Richie keeps acting rashly and letting anger guide him, tells the young man he must follow his own path now.

Richie moves to a safe position as Mikey is killed by a train, forced to absorb the man's Quickening energy because of their proximity.

Originally intending to kill the man in revenge, Richie decides to be satisfied that the former criminal and recovering addict now at least knows he took Tessa's life.

[11] Richie's career is cut short when he is seen seemingly dying, forcing him to leave behind that life and operate clandestinely for a while with Duncan's help.

Forced to fight his old friend, MacLeod kills Coltec but is then himself corrupted by the Dark Quickening, attacking Richie afterward as a result.

Though MacLeod later recovers his true personality, Richie is traumatized by their encounter and concludes that friendships between immortals are meaningless since in the end there can be only one.

Determined to protect himself by increasing his power, Richie spends months challenging other immortals and taking their heads, using the skills Duncan and Charlie taught him.

Duncan later brings him a new sword, a rapier belonging to Graham Ashe, an old teacher of the Highlander's (and of Juan Sánchez-Villalobos Ramírez) who died at Clay's hands centuries before.

Jennifer approaches Richie romantically and he spends the night with her, later confused why he would do so and believing part of Alec's Quickening drove him.

Jennifer attempts to kill Richie but then the young man briefly assumes Alec's voice and persona, pleading for mercy.

Regarding the original interpretation of the character, actor Stan Kirsch said, "Richie is a streetwise, street smart, seventeen/eighteen-year-old guy, who's had kind of a rough time growing up.

"[20] Regarding the relationship between Richie and Duncan MacLeod, Associate Creative Consultant Gillian Horvath said, "Here is this new kid on the block, just learning the ropes and having the best mentor in the world.

On set, Vandervoot was actually only three years older than Kirsch but jokingly treated him as a loved younger brother due to his youthful appearance.

According to Executive Producer William Panzer, "When we cast Stan, we were just looking for a good actor and we found one, likable, charming, and building a very nice fanbase.

Another instance is in the season 1 finale "The Hunters," when Richie arrives on the barge and the immortal Hugh Fitzcairn sees him then looks questioningly at Duncan.

The producers of Highlander: The Series remarked that the show became darker and more cynical following the death of character Tessa and that Richie was a major example of this, grieving for his friend while also discovering his immortality.

"[23] Creative Consultant and Executive Producer David Abramovitz said, "You can't keep a character a street punk for years.

"[24] Executive Producer William Panzer considered the episode "Under Color of Authority" as Ryan's coming of age story, when he killed another immortal in a rage and took his first Quickening.

I know it was frustrating for Stan - he liked being in every show - but I think it helped define the character because it meant you kept seeing landmark events in his life that kept changing him...