If you get the Rainbow Drop early enough in the game, you’ll struggle to get through Dragonlord’s Castle while maintaining high HP and MP. In this case you’ll have to grind some levels first.
Note: the EXP and Gold values on this guide are based on the Nintendo Switch Rerelease of Dragon Quest. The values for this version and the iOS release were buffed by a good margin, so if you’re playing on the original NES version, the locations are the same but you’ll have to grind for longer in each place.
Getting to Level 15
If you’re still below that level, go to Rimuldar and head south, crossing the bridge and nearby the Holy Sanctum where you made the Rainbow Stone.
You’ll find Skeleton Scrappers, Chimaeras, Scarewolves and Gold Golems here. They’re all easy enough to kill and give you between 40 and 60 EXP each, except the Gold Golems, who give only 6 EXP. If you’re not in any need of gold, avoid fighting them and just run as the amount of time to kill them is not worth it for the EXP.
From Levels 15 to 17
You can either head to Damdara to fight Green Dragons, Vis Magers, Tearwolves and Cosmic Chimaeras, or go to the desert outside Damdara to fight Knights Errants and Death Scorpions, who give less EXP but are noticably easier.
If you’re grinding inside Damdara, be especially careful of Vis Magers, as they can one-shot you with Fizzle on the first turn if you start the fight low on HP.
At level 17 you’ll learn Midheal, which is a big power spike.
From Levels 17 to 20
Head south of Damdara until you reach the southern sea. Stay to the west of the bridge and near the sea and you’ll encounter many different monsters. You want to avoid them all except one: the Metal Slimes.
Metal Slimes have only 3 HP but the highest defense in the game, so many times you will do 0 damage to them, and they also flee the fights often. However, each one you kill is a whooping 775 EXP. At this level you’ll kill them often enough to make it the best spot to grind.
After Level 20
At this level you should already be able to beat Dragonlord’s Castle. However, your level can go as high as 30. If you wish to keep leveling up to make things easier, try exploring Dragonlord’s Castle to get Erdrick’s Sword (see our guide on where to find it), and you’ll earn some levels in the process. If you still want to level up more, go back to the spot with the Metal Slimes as they are still the best EXP for the end game.
Best place to earn Gold
If you want gold to buy the Fire Blade, the Silver Shield or another expensive piece of gear, the single best monster to grind is the Gold Golem. They barely give any EXP but are easy to kill, and each one will grant you 650 gold, almost 4 times more than the next best gold dropping monster, the Vis Magers.
You can find them crossing the bridge to the northeast of Damdara, to the southeast of Rimuldar or south of the Holy Sanctum.