A video game trope. In games which feature a Class and Level System, Experience Points are needed to progress the character. In some games, to gain Experience Points, instead of Leaked Experience, each character has to actually be the one to finish off an enemy to gain the experience from this.
As a corollary to that system, the healer class is screwed over. Not built for offense, the healer is not going to be able to "last hit" enemies well. As a result, he will be particularly stubborn to level up. In a multiplayer game, expect players to attempt to play a Deadly Doctor, or to avoid the class altogether. In strategy games, a typical loophole is softening the target with strong attackers and then allowing a weak support/specialist unit to make one last killing blow.
Contrast Non-Combat EXP.
Averted in Team Fortress 2, where even a relatively inexperienced medic can easily reach the top of the scoreboardnote normally it's one "point" per kill and half a point for an assist just by focusing on healing and gaining assists from kills made by other characters being healednote Medics get one point every 600 health they heal, which is chump change.
One achievement requires players to score the highest among their own team in a single round without making any kills whatsoever. It's surprisingly common for people to unlock it without specifically trying.
While averted with kills, it's played straight with some of the objectives. There aren't assists for completing objectives— if the person being healed kills the Intelligence Carrier or defends a Control Point, the Medic will only receive points for the assist, and not the objective.
Mostly averted in Killing Floor, where healing regardless of perk will earn you dosh and level up your Field Medic perk. Played slightly straighter with welding doors, which helps levels up Support Specialist but does not (as of current) help the player at the trader.
Played straight by Campaign battles in Final Fantasy XI. For reference, players get awarded experience points and Allied Notes based on actions that contribute to the battle, such as attacking enemies, taking damage, and so on. While healing other players does qualify as a contribution, you gain experience slower for doing so, compared to the above, and the maximum XP bonus caps out much lower.
Can occur in The Lord of the Rings Online, although not with Experience Points, since everyone in the group gets them. Certain skills can, if used enough times, get upgrades that you can choose to use. In general it's not that hard getting those upgrades, as most of them can be gained purely through solo play. However, healers have skills that resurrects other players from death (although not at full health) which means that they need to be in a group to use them (they can not be used on yourself). The upgrades to those skills means players will return from death with even more health than without the upgrades. The problem arises when a player has to die a number of times in order for the healer to gain that upgrade. This means that a good healer who is doing his job and doesn't let anyone die, will have a lot harder gaining that upgrade than a bad healer. Not that the good healer would need the upgrade if they never let people die, but still...
Completely inverted in Warhammer Online - you will gain influence, renown and experience for killing enemies or assisting, but healers will get a portion of the rewards by healing those who dealt the damage, depending on how much is healed. Not only do you get rewards during the fighting, but by healing an ally who has recently gained rewards you also get bonuses, meaning that by throwing heals on random allies who are coming back from a battle will give points. Considering that an Area of Effect heal that restores 10% health to 5 allies in will give the healer roughly 10% of the spoils that each ally just received, per heal, it's no surprise that healers are always the top classes when it comes to the charts of earned XP and renown at the end of a scenario.
Averted in PlanetSide. While players do not directly gain Combat Experience Points for assisting players, they are rewarded every time the player you assisted gets a kill. A support player running around healing and repairing everyone in an intense firefight can make oodles of CEP. Other support roles benefit as well, such as engineer repairing AI turrets or vehicles gaining CEP for every kill, or a Galaxy pilot gaining CEP for every kill made by the players they gal-dropped.
PlanetSide 2 averts this completely, as EXP is granted simply for healing and reviving players.
Until about a year after its launch, League of Legends did not reward healers for the achievements their patients got and the healing characters as a whole were seen as collective gameplay scrappies. This was eventually rectified.
Rectified to the point where Sona gets assists for simply being nearby due to her aura effects. Exactly how speeding up Karthus in your base while his ultimate kills someone at the other end of the map qualifies as helping him is unclear. Also, if you are Zilean, you can ultimate someone to enable him to resurrect on death, completely waste it because your patient doesn't actually die before it wears off, and still get an assist.
Well, for Zilean it is much the same effect as healing someone who would not take enough damage to die anyway, you could at least make the argument it allowed them to be more aggressive.
Yet if you are Rammus you still don't get assists for taunting players unless you have Defensive Ball Curl up and they hit you. Pulling them into a tower will not give you any reward.
Healers in the current metagame do not scale well with items or levels compared to any offensive champion. This means support players cannot farm whatsoever and are supposed to leave all of the gold to the team's carry. As a result, healers are utterly weak and insignificant during the second half of a match and their role can be summed up as "ward bitch" - get a few cheap items that generate gold, use said gold to buy tons of wards in order to reveal enemy movements, and stay the hell away from combat. Still, four well farmed champions on a map lit up like a Christmas tree will always defeat five champions that shared their farm and are playing blind, so picking a support champion is a free win if the other team doesn't have one.
Averted by World in Conflict: in their pursuit of intense cooperation between players, the dev team awarded huge points to repair tanks for repairing things and to transport units for transporting troops. This quickly led to players driving their own units around the safe areas of the map, getting top scores without actually participating in combat, so an early patch removed transporting scores and reduced points for repairing your own units. Still, the repair+AA combo remained the top-scoring role in the game.
In the text based Grendel's Revenge, monsters who took the Shaman healing class as a primary had a doozy of a time, since new skill points were dumped into healing skills primarily and attack relegated. Poor build sequencing could lead to players being unable to kill their solo spawn. Eventually this was rectified when healing itself (and all support spells for the Shaman) gave XP, but for a long time you had very little room for error when playing a Shaman. Interestingly, by mid-game development they had the advantage of not having to worry about XP loss from dying like the combat classes did because they could potentially chain-die so often they couldn't kill their spawn; whereas Shamen and builders gaining XP through non-combat means meant this was a non-issue for them.
A variation is in Final Fantasy VII's Limit Break system. While the whole active party gets equal EXP per battle, getting to the next Limit Break level requires finishing off a certain amount of enemies. If you're using a character primarily as a healer, such as Aerith with her healing-based limit breaks, they won't advance as quickly, if at all.
In the Tenchi Muyo! RPG, to get a character to go from level X-1 to level X, that character must land the finishing blow on X enemies. This can be a problem when trying to level up characters with low attack, like Sasami, or low movement (Preventing them from getting into attack range of an enemy), like Azaka or Kamidake.
Averted in Mech Warrior Living Legends. Players detecting enemies and then forwarding their location via a C3 computer system are granted C-bills every time a new enemy is detected, or when a detected enemy on C3 takes damage. Players using the TAG laser guidance system or the NARC missile beacon are granted a percentage of the reward C-bills every time another player's missile hits the target. Players driving the Awesome Personnel Carrier receive C-bills every time a player spawns at it, buys weapons, or ammo from it.
In Disgaea, Healers are sub-par at everything except healing, not quite as speedy as frontline units, and squishy as all hell. Healing does count toward leveling up the spell you used, and the Staff skill if you use one, but provides no EXP. Healers tend to lag deeply behind because of that. It doesn't help that the games are very much about the grinding, either. Team-attack formations would help, but since that Healer is a bit slower, dragging one along to level them will slow down those already-tedious grinds.
This was corrected in the second game and onwards. Healers gain EXP for healing in every game except the first one... But they still only gain Mana from knocking out an enemy, and Mana is needed to increase the area of spells they know and to learn new spells. Fortunately, there are ways to leak mana from one character to another.
The best way out is a potential Game Breaker. If healers learn offensive magic via reincarnation or apprenticeships, their large mana pools and high caster stats can make them more dangerous than similarly leveled combat magic classes.
There are also maps with Geo Effects that turn healing to damage and vice versa. Plant the healer on a tile and she is now a one-woman nuke who whon't get killed by anything except enemy healers, which are rare.
Age of Wonders avoided the problem by giving the healers a ranged attack.
Super Famicom Wars and Days of Ruin require a unit to deal damage to gain experience at all. It's even worse in Days of Ruin because you need to get kills for any experience, and you don't even get any major stat boosts at all.
Game Boy Wars 3, however, subverts this trope, as most non-combat tasks actually provide decent experience.
Shining Force plays this pretty straight with the staff-wielding healers, but the monk characters avoid this by having respectable attack power as well as healing magic. This is especially true in the second game, in which Master Monks are very powerful melee fighters. The second game also awards huge amounts of experience for each Cure spell cast, making the healers level up faster than everyone else.
The first Fire Emblem had this, as healers did not gain experience from healing, but instead would get it from being hit. They got as much as with a kill, so with a HP-recovering terrain such as a fortress nearby, they could Boss Abuse and get to a high level fast. Would count as a Game Breaker if all the healers of the first game didn't have low-ass growths...
The second game, Gaiden, also prevented healers from gaining experience through healing. The good news, though, is that healers started with an attack spell that did grant experience, although its inaccuracy could still make healers difficult to level.
Double Subverted in some later games, where they do gain experience from healing, but it's so low unless you go out of your way to train them they'll still trail far under the rest of the team. Other games avoid this by allowing to Level Grind, using Bonus Experience on them or simply making staffs give tons of Exp.
The sixth game had this problem not with the healers, but with the merchant. He can only be leveled up by being attacked (not necessarily being hit, which is good because he can't really take a hit). 1 point at a time. It takes 100 just to gain one level.
Played with in Gadget Trial. The medic's healing command to other units does not give experience, but they still get experience by capturing buildings.
Averted in Final Fantasy Tactics Advance and the sequel, where experience is granted for all actions on another character, including allies. Since the experience gain only depends on the level difference, healing can easily net more experience than combat.
In the X-COM games (original and reboot), using a medkit on a wounded soldier is not on the list of actions that give experience towards improving stats or being promoted.note The original series had soldier statistics that increased more or less independently of each other and had nothing to do with ranks, whereas the remake directly ties statistics to rank.
Early Super Robot Wars games gave no experience for healing, but it became standard from Super Robot Wars F onwards, mostly to give poor combat units but good medics a chance to level up as well.
Averted with the Priestesses in Dungeons, who'll gain Soul Energy by healing other heroes. A good ol' fight will usually fully replenish a Priestess' Soul Energy gauge, while other heroes will need more time to reach such a level (usually by either fighting monsters or pillaging your vaults).
Battle for Wesnoth mitigates this trope somewhat; while the best XP gains come from outright killing things, units still gain some XP for fighting an opponent without killing it, and healers tend to have more powerful leveled forms to make up for being harder to level.
Healers and medics in Makai Kingdom gain a little exp by healing, but no mana, so they'll lag behind... until you find the Syringe weapon. The Syringe uses the Res stat for damage, which is also used for healing, and thus prioritized by the Healer. In other words, once you get your hands on a Syringe, your Healer will transform from a meek backrow reserve to a deadly fighter.