Kill at least three players with a single detonation of sticky bombs.
This achievement can be extremely easy if you play a good defensive Demoman. Stick back in your base and lay stickies in smart places. Chokepoints are the best places, as enemies will have to move through your sticky bombs in order to advance. When you see three enemies near your sticky bombs, detonate them. It's easiest to get with a full sticky bomb explosion (8 bombs) so plant up to your maximum. You can also do this with the Scottish Resistance, although you will have to be looking at the stickies themselves in order to kill the enemies, so it's more advisable to do it with the normal sticky launcher.
Farming this is also very easy. Get three friends and have them stand next to each other. Plant a bunch of sticky bombs at their feet and detonate them. You now have the achievement. Interestingly enough, this also works with friendly players, so if your teammates are willing to lay down a brief sacrifice on a friendly fire server, you can get this achievement right away. Once again, don't go killing friendly players to get achievements unless they consent. That's just uncool.
Note: This achievement is a reference to the traditional Scottish instrument of the bagpipe. It's also a possible reference to pipe bombs, a sort of improvised explosive.
Kill 20 spies within 5 seconds of them sapping a friendly building.
A perfect achievement for the defensive Demoman, this has you assisting an Engineer as he fights off Spies from his precious buildings. It's an easy achievement, as all you have to do it lay a few stickies on the area where the Engineer built up. Once you here that sapping sound or see a sapping charge go up on the structure, detonate the bombs. Gib goes the Spy, and ding goes this achievement. Do it 20 times and you've got yourself an achievement. Perfect for the Scottish Resistance thanks to the selective bomb detonation.
To farm this, have a friend play an Engineer and make a dispenser. Have another friend play an enemy Spy who saps said dispenser. Have him do it 20 times, with you killing him each time, and you'll get the achievement. Note that the sapping can succeed, as it doesn't matter if it succeeds or not, which is a way for the Spy to get progress towards his sapping grind achievement. It's always nice to help each other out!
Note: Any fan of the movies will see this one immediately. The movie This Is Spinal Tap is a mockumentary following a clueless rock band as they tour the country, and is one of the best comedy movies ever made. A spinal tap itself is medically known as a lumbar puncture, and involves a doctor using a needle to extract cerebrospinal fluid or inject anesthesia into the spine.
Using the Scottish Resistance, kill 3 players in separate explosions without placing new sticky bombs.
This achievement underlies the fundamental differences in the Scottish Resistance: it can lay more stickies and detonate them separately, making it a much better defensive weapon, even though its activation time is considerably longer. To get this achievement, lays sticky grenades in three key chokepoints. We suggest laying five in each chokepoint, as that's enough to kill most enemies. When you see an enemy coming, detonate the stickies near him. Kill 3 enemies total across multiple detonations to get this achievement. Note that this has to be in a single life, as dying removes stickies.
To farm this, have three friends play as Scout and stand in a rough line. Plant three stickies beneath each Scout. After the stickies have been planted, detonate them in order. You then have the achievement. It's exceedingly easy to farm, as long as you have the Scottish Resistance, and you can press G after a kill to net yourself the Second Eye achievement as well.
Note: You don't actually have to get this achievement in three detonations. If you kill two players in a single detonation and kill a third in another, you will get the achievement. You can also go over the amount specified in the achievement. If you get three kills in one detonation and two in another, you will still get the achievement. You merely have to exceed three.
Kilt in Action
Kill 500 enemy Soldiers.
This is a grind achievement, so we heavily discourage the use of farming, as it is extremely tedious. This achievement is rather simple: kill Soldiers. Kill them in any way you can. Chop off their heads, club them to death, or blow them to pieces. Make sure to take advantage of your air stickies and choke points to lure the target Soldier into your grasp. Beyond that, just kill 500 of them. One of the last achievements you will receive, most likely.
Note: A kilt is a leg covering that is often compared to a skirt, albeit for men. It is the required dress to participate in the Highland Games of Scotland, but is also worn elsewhere as a sign of racial pride.
Destroy 5 enemy Engineer buildings during a single ÜberCharge from a Medic.
The companion to this achievement is the Medic achievement Medical Breakthrough http://news.bigdownload.com/2008/05/13/guide-to-tf2-medic-achievements-part-2/. Consequently, you can probably find a Medic to help you out with this achievement. Despite this, the achievement is actually quite difficult, as you can only destroy 3 buildings at most in a single Engineer nest. You will either have to go to multiple nests or wait for other Engineers to build in the same area (highly unlikely). Alternatively, you can mine the areas with sticky grenades, wait for your charge, and then detonate them immediately. Either way, it's not easy.
To farm this, you'll need a Medic on your team and two Engineers on the enemy team. Damage yourself while the Medic heals you to build up his charge while the Engineers build up 5 buildings (preferably all dispensers and teleporters). As soon as the charge is ready, lay some stickies on the nest. Wait until you are invincible, then detonate. Alternatively, lay the sticky bombs somewhere, have the Engineers build on top of it, then detonate. This will let them build a sentry, which can give you The Argyle Sap.
Note: A Tam'O Shanter is a type of Scottish bonnet. It can actually be seen in the game as the Glengarry Bonnet for the Demoman.