Fortress Survival no air: How to create a great base
This is a custom map for Warcraft 3 by Nevo and a few other people. In it, you and all the other humans play as little survivors who can build. In a few minutes, enemies will come. You need to last 45 minutes against increasingly more powerful foes and boss monsters. You can find links to download Fortress Survival here if you haven't played it yet.
The first thing you should do is wall out your base area. Some are more popular than others, but you should try to find a spot with only one (or maybe two) entrances. The less spaces to block the better! Make sure it has enough room for lots of towers in the middle. Some players like to stall by building walls around the fortress survival defenders and quickly make arrow towers. This can give other players up to 10 minutes extra to get their defenses ready. Upgrade your walls constantly until they reach the silver wall while you're doing other things.
A few arrow towers can help with early defenses. Throw a few around the outskirts of your base. You don't want to make many, as you'll be destroying them later for better towers. Pierce does almost no damage against fortress survival bosses. Those dangerous foes have divine armor. They do make quick work of any early monsters coming your way though.
Go to a far corner of your base and put a few of them down. You'll have to switch your builder if you've never played this before. It allows access to different buildings. Upgrade them when you have the time, and remember to upgrade your walls too occasionally.
Line your walls with them. Put them 1 space away, so that you can stick mechanical repair creatures (goblins) in as well later. The repair bots don't heal any farther than that. Upgrading them takes some time, so only do it when your fortress survival base is not in danger. At this point you should make more lumber mills.
It's time to build some real defenses. The best you should do is a few rock throwers, an icy tower, and flame turrets for the rest of the area you can. Ricochet and telsa towers do a lot of damage to monsters as well, but it won't help against the bosses. Bosses are immune to stun (rock tower) and magic (frost tower) in Fortress Survival, so don't build too many of them.
Create an upgrade center, a vision post near your base (for invisible bosses) and keep making more towers/mills. Two aura statues near the middle of the base can help as well. One gives your towers +20% damage, the other gives your walls +6 armor. That's about it. Remember to keep upgrading your flame turrets and building as many as you can within range. Gravity towers work ok farther out, but they take forever to build & don't do anywhere near as much damage.
Good luck defeating the Trojan! Bases that aren't in no air mode require a bit more fortress survival strategy, try it after you win.