Tower defence economy: when to save and when to spend

After playing dozens of tower defence games, I've learned that the hardest part is rarely the towers themselves. It's the economy. Spend too early and you're broke when the big wave hits; hoard too long and you're overrun before you ever cash in.

The rule I keep coming back to is to spend just enough to survive the current wave, then bank everything else toward one key upgrade. A single strong tower usually beats three weak ones scattered around the map.

Watch the preview of upcoming enemies if the game offers one. Armoured waves punish raw damage, so you might need to pivot toward armour-piercing or slow effects. Reacting a wave late is often fatal.

Finally, learn where the long sightlines are on each map. Towers placed on corners and chokepoints get far more value per shot. Good positioning stretches a small budget a long way.