Foreign masters (later known as NPC scouts) are rival monster masters the player may randomly encounter in the overworld. These monster masters have monsters that are more powerful than the surrounding wild monsters. As these monster masters are not close with their monsters, it is possible for the player to steal their monsters by either feeding them meat or scouting them, depending on the game. These monsters also have skillsets that are not native to their species, which makes them ideal recipes for breeding/synthesizing as their pool of skills to pass down to the offspring is large and varied.
Note that stealing from NPC's is the most reliable way to obtain Metal slimes outside breeding/synthesizing since they do not flee from battle. The player also obtains far less experience from metal slimes in NPC battles, making them more valuable as obtainable monsters and less valuable for farming experience.
Dragon Quest Monsters
Foreign masters make their debut appearance in Dragon Warrior Monsters. They start appearing in Traveler's Gates after the player clears G class. The type of master that appears depends on certain conditions pertaining to the nature of the floor previous to the one the player is currently at. If the player wins, the NPC will do something beneficial for the player, which depends on the type of master the NPC is. If the player loses, the NPC will take some gold and items from the player and give him a Warpwing, and the player will be left with one monster at 1 HP. The list of possible monsters depends on the total level of the player's party, and is consistent across the different types of masters. The player can steal the last monster to be defeated if given enough meat, and will require more meat to be tamed the higher the level of the NPC (which ranges from a couple Ribs to several Sirloins). Note that the player can use a Bookmark to save before engaging the foreign master in battle, in case they are looking for a specific monster to steal (since the NPC's party is generated when the player talks to the NPC rather than when the NPC is generated on the current floor). All of these monsters will have three skills that are not native to their species. If the player steals and levels up these monsters, they will learn all their native skills as well (provided their stats are high enough). Thus, these monsters can pass down a total of six skills via breeding (not counting skills that are learned via combinations of skills). Via breeding mechanics, it is not required for the monster to learn their native skills to pass them down to the offspring. The gender of these monsters are random.
Note that it is easier to encounter foreign masters in the hidden gates since the floors are smaller and more consistent.
The following are the different types of foreign masters, what they will do for the player if victorious, and the conditions required to encounter them:
- Male Warrior - The most common foreign master. Will appear if none of the special conditions were fulfilled. Will give the player a Chimaera wing and a random item.
- Female Warrior - The same as the male warrior.
- Priest - Encountered if the player collected every item on the previous floor (will also apply if no items were spawned on the previous floor). Will heal the player's monster's HP and MP completely, as well as reviving any dead monsters.
- Merchant - Opposite to the priest; will appear if the player did not pick up any items on the previous floor. Will fill the player's inventory completely with random meats (Including BadMeat and Sirloins).
- Troubadour - Will appear if the previous room was only two screens. Will give the player's party medicine that affects each of the monsters currently in the player's party, it raises 1 random stat by 20 points permanently. Arguably the most valuable foreign master to appear.
- Mage - Opposite to the Troubadour, will appear if the previous room had several screens (typically around 16). Will teleport the player to either the very last floor in the dungeon or 20 floors down, whichever comes first.
In addition, foreign masters may be encountered in the arenas in the Traveler's Gates. Their pool of monsters are pulled from the same list as the regular foreign masters, but will be one range down. The player can steal these monsters as well. However, they only have skills native to their species, which makes them no different from the regular wild monsters. Also, metal slimes can flee from battle here, and their experience yield are not reduced. If the player loses, he will be sent back to GreatTree (just like when he loses to the regular wild monsters).
Dragon Quest Monsters 2
Foreign masters return in Dragon Warrior Monsters 2, and they only appear in the generic magic key worlds rather than the main and mandatory key worlds. Here, it is far easier for the player to steal these monsters, and it is even possible to steal these monsters without giving them any meat. Note that the player can only steal from the randomly generated foreign masters. It is not possible to steal from the criminal NPC masters who appear post-game (like the godless priest or the wayward mage), nor from storyline NPC's whose battles do not have item usage restrictions (like Milayou and the Merchant in the Traveler's Key World).
Dragon Quest Monsters: Joker
Now referred to as NPC scouts. Unlike the foreign masters, NPC scouts will have a select pool of monsters that are unique to their character, and their teams will be more powerful depending on the player's progress. Another difference from the foreign masters is that NPC scouts spawn in specific locations, which are also unique to their characters. Finally, unlike in previous games, it is possible for the NPC scout to attempt to steal the player's monsters. If successful, the player will lose the battle, and will permanently lose their monster. It is not possible for the NPC scout to scout the Incarnus, however.