Having the ability to instantly cure any number of debilitating effects in the middle of combat is exactly what Lesser Restoration is designed for. It is a single action spell that can get allies back into the fight instantly.
The rules for Lesser Restoration can be found in the Players Handbook on page 255.
Lesser Restoration 5e
Abjuration 2nd Level
Casting Time: 1 Action
Components: V, S
You touch a creature and can end either one disease or one condition afflicting it. The condition can be blinded, deafened, paralyzed, or poisoned.
The rules for the Lesser Restoration clearly define its purpose. The spell can instantly remove a disease or condition affecting one creature. This is a niche circumstance but often of great significance, especially in the middle of a dangerous conflict.
What does Lesser Restoration do?
Lesser Restoration can instantly end one disease or one condition affecting a creature. The spell description provides a list of what conditions are affected: Blinded, deafened, paralyzed, or poisoned are conditions that can be removed. Anything outside of these conditions or diseases is unaffected and would require a stronger restoration spell to remove.
Can Lesser Restoration Cure Curses?
Lesser Restoration does not remove or cure curses, only conditions. The idea that it can is hold over from previous editions. The Lesser Restoration spell has reduced functionality in 5e. It may be able to provide temporary relief from a condition that is caused by a curse. This would be a DMs decision.
Lesser Restoration doesn’t prevent the condition from taking hold again via additional casting. Advanced magic such as Remove Curse and Greater Restoration are required for dealing with more advanced conditions.
Having Lesser Restoration in the prepared spell column can seem like such a waste for the majority of encounters. The conditions listed usually seem few and far between, but it can literally be a lifesaver. The conditions either make hitting the enemy significantly harder or make it easier for the enemy to hit you or your companions.
Can You use Lesser Restoration on Yourself?
If you are affected by one of the conditions Lesser Restoration can remove, you can use the spell on yourself. The spell doesn’t require sight, so even if you are blinded, you can still use it. The only way you would not be able to benefit from the spell is if you are unable to cast spells at all.
Lesser Restoration is available pretty early on for casters. That does not mean the service isn’t available sooner from NPCs. Spells like Lesser Restoration are great for temples to provide since the spell is not available to everyone and is unlikely to be prepared daily. It should be relatively cheap (for adventurers) as an available service.
Lesser Restoration, Greater Restoration, and Remove Curse
The Lesser Restoration spell is the first opportunity casters have to cure afflictions. As described previously, the list of afflictions covered by Lesser Restoration is small. It can be cast quickly to remove impairments that most frequently occur in the heat of battle as negative effects of spells and attacks.
If the afflictions are longer lasting or more severe, chances are more powerful magic would need to be used to remove those ailments. This opens the need for spells such as Greater Restoration and Remove Curse.
Remove Curse is a specialized spell that functions exactly as the name implies. Available at 3rdlevel, the impact it can have is significant. It allows the caster to break a curse, allowing a character to remove a cursed item they are attuned to. It also allows the caster to remove all curses affecting a creature.
Greater Restoration is available at 5th level. Through positive energy, you can undo a debilitating effect. Greater Restoration can cure a point of exhaustion, petrification, charm, and break attunement to cursed items along with removing one Curse.
You can also repair damage to ability scores and hit point totals. As the spell increases, so does the cost; to cast Greater Restoration, you need 100GP of diamond dust for each casting.
The Lesser Restoration spell serves the purpose when there is a need. Depending on the circumstance, the spell is a must-have or a never-need type spell. This makes it hard to determine how important or good it actually is.
If it is possible to prepare the spell without major sacrifice, such as at higher levels, it probably isn’t a horrible idea. At low levels, the effects suffered are more debilitating, but spell slots are also significantly more restricted.