Strategy
In most word games a guess costs a turn. In Overspell a guess costs letters, and letters cost chips. That changes what a good guess looks like.
Your ten free letters are your scouting budget
The first ten different letters you play cost nothing. That is two full guesses with no repeats. Spend them on letters that tell you the most: the common ones, like E, A, R, S, T, O, I, N and L. A free letter that rules out half the alphabet is worth more than a clever guess that repeats itself.
Repeating a letter inside your free ten wastes them. Every repeat is a use you have already spent, so it is charged even while you still have new letters left.
A third fresh word is not free
The obvious trick is to keep guessing words with no letters in common. It works for two guesses. On the third, every letter is past the cap, and each new letter costs one chip.
Five chips for one guess is a lot when the day starts with twelve. The cap exists because, without it, that chain of unrelated words won every game. Scouting is still worth paying for sometimes. Just know the price before you do it.
Overdrafts climb, so spread them out
Every letter gets one free use. After that, the same letter costs 1, then 2, then 3. Using one letter four times costs 6 chips. Using four different letters twice each costs 4.
SLEEP uses E twice more after CRANE: the first extra E costs 1 and the second costs 2. S, L and P are new and still inside the free ten, so they cost nothing.
Build around your greens
A green letter is free forever, but only in its square. Keep your greens where they are and they cost nothing. Move one and it is charged like any other repeat.
S, A and L stay put in SHALT, so they are free. T moves, and it is T’s second overdraft, so it costs 2. The price shows before you press Enter. Read it.
Watch the starting stake too. Most days start with 12 chips. A day with 14 or 16 has a repeated letter in the answer.
When going over is worth it
You can always submit a word you can’t afford, and a correct guess wins even if it takes you below zero. So if you are nearly sure of the answer, play it. A guess you can’t afford that is probably right beats a cheap probe that only tells you what you already suspect.
The cost is real, though. A wrong guess past zero is a bust, and a bust ends your streak. Go over when you believe the word, not to see what happens.