Warcraft: Orcs & Humans/Regent

Building the five remaining Farms and a Barracks will cost 2000 Lumber and 3100 Gold in total. The nearest Gold Mine, east of your Town Hall, has 3000 Gold left, so it's possible to achieve this without needing another Gold Mine if you only train two more Peasants. None of the Orcs attack unless approached, so only move your Peasants to mine Gold to the east, and harvest Lumber to the northeast.

Select your Peasant to build a second Farm, and select your Town Hall to train a second Peasant. Once completed, select both to mine Gold until you can train a third Peasant, then select two to harvest Lumber: the east Gold Mine is so close that a single Peasant should be able to mine all but 100 Gold before the other two harvest 1700 Lumber to build the remaining Farms and a Barracks. Once all necessary Gold has been mined, select that Peasant to build.

While you wait for your Peasants to supply sufficient Lumber and Gold, you could do nothing (except perhaps open the Main Menu, select Options and increase Game Speed to Fastest) or you can select your three Footmen and send them on a search and destroy mission. All three will almost certainly be killed before they kill every Orc, but they should be able to find and secure Gold Mines further to the north- and southwest of your Town Hall without loss.

Arrange the three Footmen in a line perpendicular to the direction in which they move and attack. The Gold Mine to the southwest is only guarded by a Grunt, so move down the road to the southwest and attack and kill him when attacked. The northwest Gold Mine isn't closely guarded (a Peasant can move between it and your Town Hall without the Orcs intervening), but to be completely safe, move in single file through the trees to the north of the southwest Gold Mine to kill the Grunt guarding the north road, then move northeast to kill the Grunt between the trees to the northwest of your Town Hall. The Spearman to the west of the northwest Gold Mine is too far away to become aware of any mining Peasants, but could also be killed without loss.

The Gold Mine to the southeast is more heavily guarded, by a Grunt on the left and a Spearman on the right: kill the Grunt first to improve the chances of none of your Footmen being killed. The last remaining Spearman guards the southwest road, while the last remaining Grunt is to the southeast of your Town Hall, between the lakeside and the trees. If you want to kill them all, make sure a Barracks has been built first so that more Footmen can be trained to replace any killed, and that you have secured another Gold Mine to pay for them.