Evolving Attack

An ability which is subject to growth or refinement. This can go hand in hand with repeated battles although it is usually outside the explicit realm of Level Grinding. It usually just requires you use it in battle enough times.

May be a method to unlock a Magikarp Power.

Action Adventure

 * In Castlevania: Portrait of Ruin, Johnathan is able to strengthen his Sub Weapons by using them in battle a number of times. Some of these weapons gained additional effects if raised to their maximum levels, as well.
 * Castlevania Order of Ecclesia has attribute points for each attack type/element. They can be increased by either killing enemies using the corresponding type of attack, using "Drops" that come in several colours, each one raising the attribute points of a different attack type or absorbing glyphs which increases each attribute by 1. Every 328 or so attribute points equals an extra point of attack power when using glyphs of that type.
 * In Chelsea and the 7 Devils, Chelsea's Spread Shot gets wider as she defeats the Devils.
 * Your main combination attack in Alundra 2 gets longer as you find the puzzle pieces.
 * In The Guardian Legend, increasing the Guardian's Energy Chip count increases the speed and spread width of her normal energy cannon.

Hack and Slash

 * Leveling up weapons in Drakengard allows Caim to combo longer chains of attacks and unleash more powerful versions of the weapon's associated spell.
 * Similarly, leveling up a character's weapon in the Dynasty Warriors games unlocks longer combos and more powerful Charge Attacks.

MMORPGs

 * Photon Arts in Phantasy Star Universe can be leveled up through spamming them repeated usage.
 * World of Warcraft now makes all its attacks evolve passively. Before patch 4.0.1, new abilities (and upgrades to known ones) were obtained from your class trainers at certain levels. The patch does away with this requirement; now, abilities are only learned once when the level requirement is met, and their effectiveness scales up as the player's level increases.

Platform Game

 * In the Ratchet and Clank series, starting with Going Commando, each weapon had an experience meter; when it was filled, the weapon would evolve into a better version of itself. Up Your Arsenal added a five-level system, wherein levels 2-4 resulted in incremental increase in ammo capacity, range, and damage, with the fifth level being a radical change in appearance, area effect, and even name, adding a mass-destruction effect to almost all weapons. Deadlocked, however, went crazy, with up to ten levels available on the first playthrough. All but the tenth consisted of a modest damage upgrade, and an additional mod slot with a free exchangeable weapon mod to go with it. In the New Game Plus, weapon levels went all the way up to 99, each just increasing power.
 * The first two games in the Mega Man Zero series had you use your weapons repeatedly to get their full use unlocked--for example, charged attacks and the three-hit Saber combo were unlocked in stages. By the third game, this was dropped.
 * In Hard Mode, weapon upgrades are disabled, forcing you to adapt your gameplay strategy.

Role Playing Game

 * In MARDEK, powers come attached to items, but if you use a power enough it becomes "mastered" and you can then keep the power if when you remove the item.
 * This is also how it works in Final Fantasy Tactics Advance.
 * Most of your upper-level techs in the Tales of... series of games are unlocked by using a previous technique enough times. This can also gain you attacks that are combinations of more simple techniques.
 * Also in some games (particularly Tales of Vesperia), this actually happens to artes rather than just unlocking a new, more powerful version. Many artes get bonuses depending on usage such as the ability to perform them in midair or gaining more hits, and spells sometimes get "extensions" where they do additional animation and damage.
 * The most notable example in the series may be Tales of Symphonia. You start off by obtaining several level-1 techniques. You then start obtaining level-2 techniques, which mostly include powered up versions of the level-1 techs. There are also level-3 techs, which include combinations of two weaker techs alongside even stronger variants of level-2 techs.
 * Final Fantasy II had you level up each spell separately.
 * Also, effective use of weapons and shields required that you level them too.
 * In addition, the Limit Break system in Final Fantasy VII were gained via using them more often, or killing a certain number of enemies after obtaining one, except the Level 4 versions. Tidus's Overdrives in Final Fantasy X are gained the same way.
 * In all the games with Blue Mages and Goblin Punch, the ability starts off pathetically. However, as you use it more and more it can quickly become a strong move as the damage increases each time and always deals full damage. It can become your main means of damage until you get some of the more powerful weapons, especially if gained early enough in the game and used regularly.
 * In Kingdom Hearts II, each of Sora's Drive Forms (whose useful bonuses are often carried over to normal play) are leveled up by defeating specific enemies, or by fighting in specific ways. Sora's Summons also have levels increased in the same way, though this "summon level" is shared by the summons instead of separate.
 * In Legend of Mana, all special abilities and even most basic combat techniques were learned by using other basic combat abilities. Some of these made sense, such as combining Crouch and Dash to slide forward, and could even be done simply by using both of those techniques at the same time even before Slide is mastered. In other cases, this becomes rather random, with Jump teaching you how to create a black hole with your staff.
 * Characters' Deathblows (special attack combos) in Xenogears are learned by using regular attacks in different orders during combat a number of times.
 * All of the 'Killing Blow' special attacks in Star Ocean the Second Story could be enhanced by using them repeatedly in combat, leveling up into stronger, and often more spectacular, versions. The sheer number of Killing Blows available, and the number of levels many of them could be trained to, meant that without serious grinding, only your most favored attacks would ever get to the highest level.
 * Unfortunately, some of them level themselves into Awesome but Impractical territory, namely Claude's Head Splitter. From being a Death From Above attack to being completely useless, after the spin is added it almost never hits.
 * In its sequel, Star Ocean Till the End of Time, spells became more powerful the more you used them. For example, leveling up Ice Needles would allow the caster to shoot out more needles and leveling up Fire Bolt would increase the number of fireballs you'd release.
 * Hybrid Heaven by Konami is probably the king of complex Evolving Attacks. The character first learned a move (by having it used against him) and then gained levels in it by using it over and over again. However, each use also increased the Attack power of the specific body part used in the process, so a left punch would increase the Left Arm's attack, and so on. Defense was increased in each body part by taking hits in the part. Finally, for reasons this editor never determined, HP increased over the course of the game as well, depending perhaps on the number of fights encountered.
 * That's not even mentioning the secret "Combo Attacks" you could learn, by using 6 separate attacks in a particular order... and then level up themselves, no less.
 * Grandia and its sequel did this with its magic system -- each use of a spell added points to the spell and to its associated element; each new element level gives you new spells. In the first game, you could easily level up your healing/water magic by repeatedly running into a fire trap or acid pool, then healing the party. Somewhat esoterically, levelling up individual spells primarily affects the speed at which it can be used.
 * They did the same thing with weapons too, with each type (sword, axe, bow, etc.) as a separate skill to level up. Some special attacks required you to level several weapon types to a certain point before you'd earn them, forcing you to change your weapons around often. Some of the (usually elemental-based) special attacks even required you to have a high level in one or more magic groups as well as weapons.
 * In Wild ARMs: Alter Code F, the more you use Jack's moves the less MP they consume. (In the original version, this was done by using certain consumable items on the attacks you wanted to cheapen.)
 * Both weapons and elements of spells in Secret of Mana could be increased in skill level through repeated use. For weapons, increasing the levels unlocked special abilities that could be used with them after charging them up, while for elements, increasing the levels simply increased their spells' power and at times upgrades their animations. However, once an element is at maximum level, it can still gain skill towards the unattainable next level, which corresponds to the chance that its spells will spontaneously turn into a special, more powerful version when cast (ie. fireballs turn in fire dragons).
 * In the Dark Cloud series, almost all leveling is done through weapons; each type of weapon can evolve along different paths, leading to a variety of ultimate weapons for the same character. Or you could just stick with the surprisingly effective Frozen Tuna.
 * Skies of Arcadia required players to use different Moon Stones on their weapons in order to learn different spells.
 * Legend of Legaia's entire fight system seems based off of this trope. Even magic gets more powerful as you use it more. The sequel plays it even straighter, as several Hyper Arts are learned by using the base forms enough times.
 * The The Lord of the Rings: Third Age makes use of this trope. To unlock new attacks and abilities the characters have to use abilities of the same class.
 * Handled in a literal manner in Gothic, as an in-game explanation of how Nameless Hero gets better at using weapons. Visually, this is represented by the character changing his battle stance and grip on weapon as he levels up weapon proficiency skills, as well as longer and more effective Combos.
 * Secret of Evermore required that you level up your alchemy recipes with constant use before they start getting potent, sometimes restricting you from overlevelling the stronger magics since you needed (often rare, sometimes finite) ingredients each time you cast them. There's more than a few common-ingredient formulae that can become Game Breaker overpowered though.
 * Gabe's, Tycho's and the player's stats can be increased in both (so far) of the Penny Arcade Adventures games. Finishing off an enemy with a perfectly-executed super move kills your enemy in a gory way, which gave you an Overkill mark, which permanently increased your strength. Each character can get 15 Overkill marks (5 per weapon level, with three weapon levels.)
 * Both Lenneths (first game) and Alicia's (second game) Nibelung Valesti in the Valkyrie Profile series evolved as the game moved on.
 * Cross Edge features skill levels which increase both the power of your skills and unlock new skills.
 * Most of the fighting in Legend of Dragoon is done with Additions, a series of weapon strikes performed by hitting the attack button with very specific timing. Every time you pull one off, you get a skill point in that Addition; gain enough skill points and you unlock a new Addition. Some characters only have three Additions; others have as many as seven, and there's a total of 99 possible skill points for each one...
 * Also similarly, leveling up a character's weapon skill in Koudelka adds an extra strike to the character's attacks with that weapon.
 * Pins in The World Ends With You level up in combat, becoming more powerful. And in a near-literal example of the trope, some evolve into entirely new pins, usually with even stronger versions of the same attack (though it depends on the pin, and not all of them evolve through combat). Also, a pin's growth rate isn't affected by how much you use it; you just need to have it equipped.
 * .hack//GU Redemption introduces advanced Arts that the player unlocks after leveling their weapon skill enough. This gives them a nifty new attack which improves in power and cost-effectiveness for each subsequent level in that weapon skill they raise.
 * Personas in Persona will gain ranks by using them. There are 8 ranks in total and how often they gain ranks is determined by the character that Persona is equipped to. In Persona 2 rank works exactly the same way. This and the automatic battle system will encourage you to find a group of weak Mooks and spam healing spells until your Personas are maxed out. Be sure to have some SP recovery items on you though.
 * In the Pokémon series, the moves Return and Frustration become more powerful the more or less the pokemon using them is happy with the trainer. At full power, they are more powerful than Earthquake without a boost.
 * Moves such as Night Shade or Seismic Toss do set damage based on the user's level, and can gradually turn from nigh useless to reliable weapons as your mons gradually reach the golden level of 100.
 * Doing this in Nostalgia could unlock new skills.
 * In Harry Potter and the Philosopher's Stone on the Game Boy Color when a spell is used repeatedly a more powerful version of the same spell is obtained.
 * War Craft 3's heroes have three 3-leveled and one ultimate spells that can be upgraded, one per level.

Turn Based Strategy

 * In the Disgaea series, spells can be leveled up, increasing their damage, range and area. Special attacks can also be leveled up, but--with the exception of Prinny Raid--only increase in damage.
 * Spells and special attacks in La Pucelle Tactics can be levelled up in the same way.
 * Ditto with Phantom Brave--since items technically count as separate units (they count towards how many units you're allowed on the field at once), they level up too. You can unlock stronger attacks for them by earning and then spending experience points gained by using them.
 * Final Fantasy Tactics a 2 as a few of this. The most famous is the couple evolving equipments: the sword Sequencer and the armor Peytral, whose stats grow during the course of the game as you perform opportunity commands, being up to 99 higher than the based Attack/Defense. There is also an Esper who cause more damage the more his caster has killed enemies, and Vaan has a skill that does more damage the more he successfully used the "Steal" move.

Wide Open Sandbox

 * In Shenmue for the Dreamcast, the main character's attacks all start out as borderline competent and somewhat sloppy, leaving no doubt as to why he was no match for Lan Di. The more he uses his attacks, whether in actual combat, in training sessions with his friend or solo practice, the higher his proficiency with using any move becomes. The higher the proficiency, the more graceful each attack or counter-attack manoeuvre gets, leaving fewer openings, having shorter recovery times and striking with more power and precision. This is practically mandatory if he is to defeat Chai in the arcade ambush.