Horses: Feedback and suggestions

[NegInfinity]

So. I bought my wizard a horse.

Made it etherial via greater sanctuary, told it to follow me without attacking, and went to beregost.

On the road to beregost, horse passed a goblin, who triggered an attack of opportunity (from the horse), so the horse breaks etherealness, and starts fighting the goblin. I finish off the goblin, the horse spots a tiger, and attacs the tiger. The tiger casts fear, horse gets scared and gets stuck. I finish the tiger before it kills the horse, and take the horse with 1 hp to beregost.

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I think this isn't working.

Enemy combat ai always targets lowest ac enemies, meaning they'll always go for the horse, and the horse has 100 hp and level 3. The horse is also quite dumb, meaning it will attack enemies, sometimes accidentally, and mess up attempts to properly protect it.

I think the situation could be improved in two ways:
1. Make the horse immortal and make it go down like trolls do. Then recover once the combat is over. Maybe recover with one hp. Maybe make it die for real if you get too far away from it once it is down. I don't know.
2. Add an option to spend money to improve horse level. Maybe 1 gp per horse xp. Maybe several gp. And level the horse up. If it dies, leveling process is lost, and the horse goes poof, like sigil golems/henchmen.