Tower defense games – or TD games as they are often known – are a big part of the gaming landscape today. But it wasn’t always so; their success is the by-product of a fifty-year evolution that began when elements of tower defense began appearing inside other games in the 1970s.
The defining feature of TD games of stopping enemies from invading your territory proved to be a popular one. Fan mods on popular computer games expanded the concept throughout the 1990s before game developers eventually realized that entire franchises and game worlds could be built around the mechanic.
What is it about tower defense games – be they desktop tower defense games, mobile games, or console titles – that has ensured their enduring appeal? If you have played one, you’ll know that much of the answer lies in the deceptive simplicity of the gameplay.
Ostensibly, all you have to do is deploy your defenses, destroy enemies, and repeat. But tower defense games are strategy games – and that’s where things get interesting.
Read on to find out all about how they have risen to prominence, what makes the best tower defense games stand out from the rest, and what strategies you can adopt to master them yourself.
As a game concept, “tower defense” is relatively simple. Look at any title in the genre, and you’ll see the same basic mechanic: enemies – or “creeps” as they are known in the jargon – enter from one location, and your job as the player is to stop them getting to the other side of your screen. You do this by building up your defenses which, though referred to generically as “towers”, can, in fact, be anything that impedes, damages, or eliminates your foes.
While the framework is quite straightforward, developers have built an extensive genre by exploring various themes and infusing mechanics from other genres.
One popular series of free tower defense games, for example, sees the player’s home being attacked by hordes of zombies. Repelling the undead creatures requires not guns or bombs, but plants!
Is that image – of kooky zombies, gardens, and vegetation – what the term “tower defense” brings to mind? Most likely, you pictured something more medieval, perhaps involving castles, cannons, and drawbridges. Well, those kinds of tower defense games exist too.
Indeed by now, tower defense titles encompass more or less any kind of situation imaginable. Want to ward off evil penguins? There’s a tower defense game for that. Perhaps you prefer taking on aliens – the genre has that covered. Monsters? No problem. That’s the charm of tower defense: whatever your preferred setting or historical period, there are almost certainly free tower defense games out there that cater to you.
How did this explosion of creativity come to bless the genre? To answer that question, we have to go back to the 1970s, to what is sometimes referred to as “the golden age” of arcade video games.
Do you remember those old arcade games where you used your spaceships to lay waste to hordes of aliens? In spite of their simplicity, it is now widely acknowledged that those shooters were a revolution for the video games industry.
When we look back at them now, it’s clear to see their influence on a wide range of genres, with tower defense being no exception. It can be argued that those games lay the foundations upon which today’s tower defense titles are built: rows of aliens moving across a screen that must be destroyed before they reach the other side with defenses the player can deploy to impede their progress.
Such concepts were developed further in subsequent years, with several desktop tower defense games appearing in the 1990s. Their success led fans to use free map creation tools to make their own tower defense levels in mainstream computer game mods. In many cases, the developers of those games, recognizing the trend, incorporated their own tower defense maps into subsequent releases. That helped take awareness of tower defense mechanics to a higher level.
Bigger things were still to come, however, with the advent of flash-based web games in the mid-2000s. Thanks to flash, small-scale developers were able to easily produce a title, then release it to the world. A number of tower defense titles came to fame in just that way, gaining millions of players and winning awards in the process.
Flash, as we know, was finally discontinued in 2020. But tower defense games, still built on the same basic mechanics as their forerunners, live on. Mobile game developers have taken the genre a step further by infusing it with new mechanics from RPG games and Merge games in recent years.
With so much activity in the genre, it might just be the perfect time to discover tower defense games for yourself. Before you do that, though, there are a number of things worth keeping in mind if you want to be sure your hours of gaming to come will be well spent.
Regardless of if you are playing tower defense games online or offline, the truth of the matter is that they don't usually have much in the way of a story. As a result, they tend to rely on great design and well-balanced mechanics to keep players engaged. When deciding which tower defense title or titles to invest your time in, look for the following features:
Tower defense games are inherently repetitive, but the good ones counteract this with plenty of variety in terms of creeps, towers, and maps. When there are so many possible combinations, players will always have something to think about, something new to try out, and have meaningful decisions to make.
Do maps, for example, have multiple entrances and exits for creeps? Are some towers more effective against certain types of creeps than others? Are there towers that perform well on certain maps, and poorly on others?
When a tower defense game answers “yes” to questions such as the ones above, there’s a very good chance it is worth your time.
The best tower defense games get the balance right between being accessible to beginners, and providing a deep, challenging longer-term experience. They provide a continuous sense of progression for the player.
Many modern tower defense games have done this by incorporating elements from RPG games. So, you can develop your defenses, discover new characters to aid your bastion, and level up as you go along.
Look for games that have a lot to discover and you won’t go wrong. The best ones are designed to grow in complexity to match your improving skills so you always have a challenge to look forward to.
At heart, tower defense games are strategy games. As such, in order to succeed, they should have a clear and easy-to-use interface that provides players with the information they need to make decisions.
Next time you play a tower defense title, take a moment to study the menus and associated texts. Can you quickly and easily find out a tower’s attack range? Are you able to read about the strengths and weaknesses of the various creeps? The best tower defense games make this simple so you can focus on what matters most: strategy.
This is a genre where simply putting in plenty of hours may not be enough to succeed. To really excel at tower defense, you need a plan. Here are the main things to keep in mind:
From the very first wave of creeps up until the most difficult stretches of the game, where you place your defenses is arguably the most crucial element of success. Your decision-making will need to take into account a number of factors, such as the strengths and weaknesses of different defenses, and the paths through your territory creeps will take.
Just as location matters, so too does range. Comparing and selecting towers to build according to their range of fire will help you create an impenetrable line of defense. Keep in mind that range typically increases as you upgrade towers, so investing in existing ones can be more effective than constructing new ones.
Particularly with tower defense games online, it’s often necessary to collaborate with other players because your own resources will not be enough to stave off attackers. Always craft a holistic strategy as that is often the key to success.
Whether your enemy comes in the form of computer-controlled bots or other real players, be sure to pay close attention to how they behave. Learning their strategies – and understanding how to respond to them – is crucial to an effective defense of your territory.
Although the objectives of tower defense games might seem straightforward, the routes to victory are not. Don’t forget that there are many different ways that you can repel creeps depending on how you use your terrain, where you place your towers, and how and when you upgrade them.
At the same time, when it comes to breaching your defenses, your enemy will have a range of options at their disposal too. Always keep that in mind, and constantly adjust your strategy to stay one step ahead.
So, has your interest in tower defense games been piqued? If you’re ready to experience them for yourself, all that remains is for you to pick a platform and dive in.
If you own a smartphone, that’s a perfect place to start: there are plenty of free tower defense games out now for Android and iOS mobile devices. Equally, if you want some desktop tower defense or console action, you won’t suffer from a lack of options.
When searching, don’t worry if you find tower “defense” games and tower “defence” games, as the change in spelling is just a product of regional variation. If in doubt, simply search for “TD games” and you can’t go wrong.
Tower defense games truly embody the concept of “pick-up-and-play”. But be careful, because once you get drawn in, you won’t want to put them down until you’ve destroyed every last creep!