Introduction
To state it at the start I believe that everyone should be able to ride a horse/mount after observing other people ride for a few minutes, but it should have very little response to your input till you train, the stress bar would increase vastly quicker the least trained you are and your stamina bar would deplete at a much faster rate.
Riding is crucial for the long-distance travel many expect to have in the game and also for general horse/mount usage and as such it should be as fully fleshed out as some of the more mainstream skills/professions that will be in Elyria. Not only that it would add into the feel of the game due to it being a valid playstyle for a player to have his/her characters getting involved in and show visible progression for it.
Training
You would only be able to do basic walk and limited trot till you practice for a little while till you are able to reliably trot this is when your character's personal stamina/fatigue replenishment rate increases and the rate at which it diminishes, decreases as the character's body is getting trained for the physical process of riding.
The horse could provide auditory and visual feedback for the rider so if the horse smells some canis rabbits in a bush or a bandit in a bush etc.. it could provide some feedback to the rider such as making noises such nickering, blowing etc.. with head and ears pointed towards the direction of the bush, that could give the player a choice to move around the area if the player doesn’t want to fight or face whatever the horse senses.
It is not just physical traits that get used by the character but mental and social ones as well;
As shown in the attribute matrix there are 3 main divisions; Physical, Mental and Social upon which they are further divided into Force, Reflex and Endurance.
To narrow it down I suspect the three main attributes a player should get his/her character to work on if they want the character to be a skilled rider would be;
Stamina - Riding can be a very enduring profession it can be just as tiring for the rider as is for the horse.
Will - Riding is a matter of willpower, you must be willing as a rider to input your requests to the horse and keep at it till it is done. The horse must know you are serious about what you want it to do, Leadership also ties into it as the horse sees you as it’s natural protector so you must be able to transplant your leadership into the horse to get it to respect you.
Intuition - Riding requires a certain “feel” as you sit in the saddle and if you are trained for it you can detect what the horse is about to do just be subtle posture movements, ear movements etc.. Higher the Intuition the least likely it is for the horse to be scared as your character can react to it using intuition.
This is where two bars can be used on the UI of the animal that you are riding, Stress and Stamina, the more the horse is scared the more the stress bar increases and higher the stress bar the more likely the horse will kick out and misbehave/bolt off with you on or off the mount.
To clarify the stress bar relates to the horse and not the rider.
However it would depend on the horse as well, each horse could have different tolerances to stress and breeding, training etc.. would have an impact on those tolerances.
Stamina bar could be either the mounts stamina or the characters physical stamina, the more trained the rider the more efficiently the mount is ridden so the energy used by both horse and rider decreases the stamina drain on the horse and rider - Energy bars have been mentioned by Caspian in the past - it could be a good idea for dramatic storytelling if a horse could flee with you on the back even though you're unconscious! In that case the rider's energy bar would be down to zero. So maybe we could make it to be so that it drains from both the “energy bars” of the rider and horse?
This means that the energy drains at different rates because the horse could be well more trained and endure a lot better than a novice rider..
This means that a rider will need to ride a horse suitable for the skill level for that individual as otherwise the rider might not be able to keep up with other riders who are riding suitable horses for their ability levels and physical stature/condition
However; Some of this can be sidestepped if the horse goes through an area it frequents a lot so for example a paved road along a trade route a cart horse uses a lot would be much less stressed than if the horse is in unknown territory.
That is an incentive to using the same horses for a role as they are trained and accustomed to that locale. Essentially long term travel will require multiple horses if you do not want to make pit stops to rest but eventually you will need to stop though as your stamina would drain
Progression
The average character who uses a horse as purely transportation from A to B will only need to reach Apprentice, which would be easy to achieve.
However to get past apprentice you will need to get training from trained riders and facilities, this is where dedicated training facilities are in order, so menages, 20x40metre and 20x60metre arenas come into being.
You can train for a number of different branches in riding utilising these resources (and additional ones as well, such as trot poles and jumps), some of these could be;
Technical - Focusing mainly on the responsiveness of the horse to the rider, good for nimble light cavalry and similar.
Jumping - As name implies, decreases stamina drain when jumping and allows the horse to jump to it’s potential (again it is down the genetics and stature of the animal, a little 11hh pony is not going to jump 4ft jumps often, a 18hh could, however.)
Endurance - Long distance riding at speed, decreases stamina drain and increase performance on rough terrain.
Essentially you will need to work towards whatever you aim to do with riding, you want to cross rough terrain quickly? Practice using trot poles and small jumps to get the horse’s balance to a good level and do long sessions to build up the endurance of the horse for example.
