To evolve or not to evolve? That is the question. Evolution has good points and bad points. You just have to look at the situation from all angles, and decide from there. This guide will not only help you decide when, or if, to evolve your Pokémon, but also gives some information on several types of evolution.
In the world of Pokémon, evolution could be the equivilant of growing up. Pokémon that have evolved generally look larger and tougher or scarier. However, this is not always the case. Some Pokémon evolve into ones that are much cuter or more beautiful than the pre-evolution. However, where some Pokémon's evolutions are so similar it hardly seems worth it to have another, some can be very different. Pokémon can evolve through several methods, usually by leveling up, but also by trading, using an evolutionary stone, friendship, and other events.
An evolved Pokémon almost always has higher stats than a non-evolved Pokémon. Take a look at two Pokémon's base stats, Lileep and Cradily.
| Stat | Lileep | Cradily |
| Hit Points | 66 | 86 |
| Attack | 41 | 81 |
| Defense | 77 | 97 |
| Speed | 23 | 43 |
| Special Attack | 61 | 81 |
| Special Defense | 87 | 107 |
The evolved form has better base stats, and this is the case with almost all evolutions. No matter when you evolve your Pokémon, the stat boost will be the same, so you just need to decide when you want it.
When a Pokémon evolves by level, it usually learns almost the exact same set of moves as its pre-evolutions. However, the level at which these moves are learned are higher in evolved Pokémon. The Pokémon Marill learns the move Hydro Pump at level 45, but Azumarill will learn it at level 57. In some cases, the evolved form will be able to learn additional moves.
If the Pokémon evolves through use of a stone, however, it usually can learn very few, if any, new moves afterwards. Because of this, whenever you evolve a Pokémon with a stone, be sure you're satisfied with its moveset.
And lastly, an evolved Pokémon may be able to learn from more TMs and HMs than the pre-evolutions. Moves like Hyper Beam and Strength usually aren't teachable until the final stage.
Some Pokémon evolve to their next stage by what is called a stone. There are several types of stones, the Sun Stone, Moon Stone, Fire Stone, Water Stone, Thunderstone, and Leaf Stone. Introduced in Diamond and Pearl are the Shiny Stone, Dusk Stone, and Dawn Stone. Some of these stones can be bought at a department store, others can be won from events, and some can only be found on the floors of caves. The following table shows what Pokémon use which stone to evolve.
| Stone | Pokémon | Evolution |
| Sun Stone | Gloom | Bellossom |
| Sun Stone | Sunkern | Sunflora |
| Moon Stone | Nidorina | Nidoqueen |
| Moon Stone | Nidorino | Nidoking |
| Moon Stone | Clefairy | Clefable |
| Moon Stone | Jigglypuff | Wigglytuff |
| Moon Stone | Skitty | Delcatty |
| Fire Stone | Vulpix | Ninetales |
| Fire Stone | Growlithe | Arcanine |
| Fire Stone | Eevee | Flareon |
| Leaf Stone | Gloom | Vileplume |
| Leaf Stone | Weepinbell | Victreebel |
| Leaf Stone | Exeggcute | Exeggcutor |
| Leaf Stone | Nuzleaf | Shiftry |
| Water Stone | Poliwhirl | Poliwrath |
| Water Stone | Shellder | Cloyster |
| Water Stone | Staryu | Starmie |
| Water Stone | Eevee | Vaporeon |
| Water Stone | Lombre | Ludicolo |
| Thunderstone | Pikachu | Raichu |
| Thunderstone | Eevee | Jolteon |
| Shiny Stone | Roselia | Roserade |
| Shiny Stone | Togetic | Togekiss |
| Dusk Stone | Misdreavous | Mismagius |
| Dusk Stone | Murkrow | Honchkrow |
| Dawn Stone | Kirlia (male) | Gallade |
| Dawn Stone | Snorunt (female) | Froslass |
As I stated before, the Pokémon that evolve from a stone rarely learn moves after evolution. The Eevee evolutions, however, are capable of learning many moves afterwards, and their movesets are often completely different from Eevee's, due to the change in type.
Some Pokémon evolve only after you trade them. For these Pokémon, the movesets hardly change. Some Pokémon must be traded while holding an item in order to evolve. These Pokémon are listed below.
| Item Needed (if any) | Pokémon | Evolution |
| ---- | Kadabra | Alakazam |
| ---- | Machoke | Machamp |
| ---- | Graveler | Golem |
| ---- | Haunter | Gengar |
| King's Rock | Poliwhirl | Politoad |
| King's Rock | Slowpoke | Slowking |
| Metal Coat | Onix | Steelix |
| Metal Coat | Scyther | Scizor |
| Dragon Scale | Seadra | Kingdra |
| Upgrade | Porygon | Porygon2 |
| Deepseatooth | Clamperl | Huntail |
| Deepseascale | Clamperl | Gorebyss |
| Protector | Rhydon | Rhyperior |
| Electrizer | Electabuzz | Electivire |
| Magmarizer | Magmar | Magmortar |
| Dubious Disc | Porygon2 | Porygon-Z |
| Reaper Cloth | Dusclops | Dusknoir |
In order for some Pokémon to evolve, they must have grown a bond of friendship with you. A Pokémon's friendliness towards you can be increased by battling with that Pokémon, grooming it, carrying it around in your party, etc. Once that Pokémon has reached the right level of friendship, it will evolve the next time it grows a level. Some Pokemon require a certain time of day to evolve, as well. The following Pokémon evolve with this method.
| Pokémon | Evolution | Time of Day |
| Golbat | Crobat | ---- |
| Chansey | Blissey | ---- |
| Pichu | Pikachu | ---- |
| Cleffa | Clefairy | ---- |
| Igglybuff | Jigglypuff | ---- |
| Togepi | Togetic | ---- |
| Azurill | Marill | ---- |
| Eevee | Espeon | Daytime |
| Eevee | Umbreon | Nighttime |
| Budew | Roselia | Daytime |
| Buneary | Lopunny | ---- |
| Chingling | Chimecho | Nighttime |
| Munchlax | Snorlax | ---- |
| Riolu | Lucario | Daytime |
Diamond and Pearl introduced several new ways for Pokémon to evolve, one of them being evolution by moves. When a certain Pokémon knows a certain move, it can evolve, regardless of level.
| Move Needed | Pokémon | Evolution |
| Double Hit | Aipom | Ambipom |
| Mimic | Bonsly | Sudowoodo |
| Mimic | Mime Jr. | Mr. Mime |
| Rollout | Lickitung | Lickilicky |
| Ancientpower | Tangela | Tangrowth |
| Ancientpower | Yanma | Yanmega |
| Ancientpower | Piloswine | Mamoswine |
Introduced in DP, certain Pokémon will evolve only in certain locations.
| Location | Pokémon | Evolution |
| Mt. Coronet | Magneton | Magnezone |
| Moss Rock | Eevee | Leafeon |
| Ice Rock | Eevee | Glaceon |
| Mt. Coronet | Nosepass | Probopass |
Also introduced in DP, some Pokémon can only evolve when they are holding a specific item.
| Item | Pokémon | Evolution | Time of Day |
| Oval Stone | Happiny | Chansey | Daytime |
| Razor Claw | Sneasel | Weavile | Nighttime |
| Razor Fang | Gligar | Gliscor | Nighttime |
As of now, the only Pokémon that evolves due to a contest stat is Feebas. When you have maxed out Feebas's beauty stat, once you level Feebas up, it will evolve into Milotic.
There are two Pokémon that don't really fit into any other categories. In order to obtain Shedinja, you must have at least one Pokéball and one empty party slot when you evolve Nincada. And Mantyke will only evolve into Mantine if you have a Remoraid in your party.
I hope this guide has helped you, and good luck in obtaining your evolved Pokémon!
