Baseless Mission

Typically in strategy games you are given or have to build a base, so that you can have an endless supply of units as long as you have access to resources, and you can rebuild destroyed buildings.

However, in this mission (it is usually a campaign mission) you don't get such a luxury. You get a handful of units, and you must accomplish your goals without losing all of them.

This is how those missions typically work.

The premise is that you are behind the enemy lines, fleeing from somebody, or exploring a new territory.
At least one of your soldiers is a hero unit if there are any.
You lose the mission if you lose your whole army or, in some occasions, the hero.
There may be a way of getting additional soldiers, especially if you are behind the enemy lines: you free them from being enemies' captives.
You may get the base back halfway into mission.
These missions typically become That One Level if the game is not suited for tactical combat well or the amount of units given isn't enough to deal with enemies.

Examples of Baseless Mission include:

Frequent in Warcraft III, where you usually get to play as a main hero of the current campaign + a handful of units.
- In Frozen Throne the whole Orc campaign is RPG-style.
Warcraft II: One of the missions involves leading a band of orcs, trolls, and Ogres to a location. They have no workers to create buildings.
- There are actually six such missions in Warcraft II and its expansion: In the original game, in mission 6 of the Orc campaign, you escort a band of orcs and trolls led by Cho'gall to a certain location.
- In mission 9 of the Human campaign, you have an army and a navy trying to escort Uther Lightbringer.
- In the expansion, the first mission of each campaign gives you no peasants (although you do have access to a handful of buildings and the upgrades that can be purchased from them).
- The seventh human mission in the expansion does give you peasants, but they can't build any military structures; and the ninth orc mission again has no peons, only a few buildings scattered across the map and a finite amount of resources to buy the upgrades from them.
Warcraft 1 also has several campaign missions like this.
A staple trope of Command & Conquer series, encountered at least once in each installment. Each hero got at least one mission dedicated to him or her. Often doubles as Stealth-Based Mission.
- Any of these missions from Tiberian Dawn apparently expected you to literally take on a base by yourself, making them quite Nintendo hard. Later literations would always add some sort of script or conveniently placed barrels to help you through the level.
You get to play as the main character exclusively in Impossible Creatures' campaign.
Empire Earth did that with Middle Ages campaign.
Age of Mythology did that a handful of times.
- Age of Empires II seems to have one in every campaign, often as the first mission. You start Joan of Arc with just Joan and a ragtag band of supporters, and while your army increases, you never get to build a base.
Warzone 2100 had two types of missions in its campaign mode: One involved searching the map, collecting your usual resources and expanding your base while fighting off enemy units and completing mission objectives. The other were "transport" missions where you loaded an air transport with a set number of units to accomplish mission objectives on a completely different map. You were, however, generally allowed to review your base's production/research schedules and arrange reinforcements from home base.
The goal of single player missions in StarCraft and StarCraft II is generally (as in multiplayer) to build up your base and defeat the enemy, but a number of missions were included where you're given only a group of units with occasional scripted recruits and you have to navigate through the map and survive. These are called "installation missions" in the fandom, because they would often take place inside Terran structures or ships on the installation map tileset.
Metal Fatigue had a level where you only had one combot and no base and had to heal it by scavenging spare parts.
Heroes of Might and Magic IV introduced these into its series in some campaign missions where you were just given a hero or several and no towns, and HOMM V followed suit. In previous games, you always lost the game in a week after all your towns were captured.
Several missions in State of War let you start with a handful of units and nothing else. Some of them let you capture enemy factories and win as usual, other (like escort missions) don't give you that luxury.
- Inversion: mission in Greece gives you a base but no means of acquiring unit factories - you have to win by building lots and lots of towers.
World in Conflict doesn't have a base per se (only stationary drop zones) but some missions in the single-player campaign where even your drop zone is taken away from you, either temporarily or for entire duration of the mission.
The fourth Imperial guard mission in Warhammer 40,000: Dawn of War: Winter Assault is a baseless Escort Mission, but actually not that bad.
- One mission in Dark Crusade is especially hard because of this. Ironically, completing it unlocks the ability to deploy a forward base when attacking other territories.
  - Strangely, the one mission where being baseless would make sense (as it happens underground), it's a stronghold mission.
- Dawn of War II however is (almost) entirely baseless. The single player campaign (up to the Retribution Expansion Pack) consists only of reinforcement points to rally around to bring depleted squads back up to full strength. The multiplayer mode has slightly more in the way of bases, in that each player has a single building as their main base, and can fortify other specific strong points, but these are pretty far removed from traditional base building.
Company of Heroes has a few. Mostly involving paratroopers, who have the ability to reinforce their squads anywhere, and could drop new squads with a support power. Since resources were gained by territory control, it was still possible to have income without a base.