Gravity is a very seldom-used move, which is a shame because it’s a useful state to put the battle in if you are prepared for it. One of the rarer and more awkwards moves, Gravity triggers five turns of ‘High Gravity’ for the battle, regardless of any swapping- making it a battlefield effect a lot like weather.
Gravity has several interesting effects while it lasts. First of all, it removes the protection that Flying-type and Levitating pokemon have against Ground attacks, making it very useful if you want to get the most out of Earthquake. Second of all, it reduces the Evasion of all pokemon by two stages- effectively increasing the Accuracy of every move by 25%. Finally, and least importantly, it disables the use of moves that require going ‘up into the air’- primarily Fly, though Bounce is also disabled.
While none of this is explicitly stated in the move or in its text when it is used in the game, these effects make Gravity a useful tool- if a hard one to get ahold of, and one that the pokemon who have access to it rarely take full advantage of.
In the game, there are only ten evolution chains that can learn Gravity: Cleffa/Clefairy/Clefable, Duskull/Dusclops/Dusknoir, Jirachi, Nosepass/Probopass, Arceus, Sigilyph, Iggybuff/Jigglypuff/Wigglytuff, Happiny/Chansey/Blissey, Roggenrolla/Boldore/Gigalith, and Ferroseed/Ferrothorn. Many other pokemon can take rampant advantage of Gravity while it’s in effect, thanks to the wealth of 70-80 accuracy moves that are powerful and the number of pokemon whose coverage becomes complete when Earthquake can hit Flying-types and Levitation pokemon, but these pokemon will get at most 3 turns of Gravity- since the turn the move is used in and the turn during which you switch pokemon both count against the five-turn total. Thus, it pays to make the most of the move while you can.
Of the pokemon that can learn Gravity, Clefable, Dusknoir, Jirachi, Wigglytuff, Gigalith and Ferrothorn can make the most use of its effect. Clefable, Dusknoir, Wigglytuff and Gigalith all benefit from the boost to Earthquake and to certain lower-accuracy high-power moves of the physical variety (Stone Edge, Mega Kick, and Dynamicpunch in particular). Jirachi, Clefable and Wigglytuff all benefit highly from the boost to accuracy with moves like Blizzard, Fire Blast, Thunder, Focus Blast, and Charge Beam. And Ferrothorn laughs maniacally as incoming Flying-types start taking damage from Spikes and getting poisoned by Toxic Spikes despite their aerial tendencies. Similarly, many other pokemon can benefit immensely- Charge Beam/Focus Blast is a nasty combination to pack on an Electric or Normal pokemon that will want the increased accuracy, and anything that runs around with Stone Edge/Earthquake for coverage will love the effects of Gravity on Weezing and Skarmory.
Packing the most power into those three turns is key, so it pays to have a look at your available moves and figure out which ones are in the right range- the ones with high power and a 70-80 accuracy rating are ideal, as that increase bumps them up to a 92-100- which turns them from semi-reliable swings into heavy-hitting staples. As long as your Gravity-user is durable enough, the team as a whole should function beautifully- there is, after all, no way to clear Gravity from the field other than waiting it out or winning the battle.
Keep in mind, though- Gravity is only really worthwhile if a large part of your team can take advantage- you’ll probably want two or three Gravity-users on the team as well, to make sure you don’t lose access. If all you’re really looking at is a single pokemon that needs accuracy or a way to hit fliers, you’re better off equipping it with a Wide Lens or changing its moveset around- or relying on another teammate for some form of boost or to take out threats. Gravity as a single or two-pokemon gimmick just doesn’t work.
