Since even novice players can spot open attacks (there are only six places to check), more advanced players organize hidden strikes. A hidden strike is when you use a sequence to open up an attack and execute the strike in the same turn. For example, you've got 1 seed in 5 and 6, and your opponent has a stash in 8. You can open the attack by emptying 6, and then short-strike with 5 in the same turn. This sort of attack is harder to spot than an open attack.

An even more advanced form of hidden strikes are concealed strikes. A concealed strike is when you increase one of your own houses in a sequence to open up an attack. For example, you've got 2 seeds in 5, and 7 seeds in 6, and your opponent has a stash in 13. You can open the attack by emptying 5, thus increasing house 6 to 8 seeds. Then you can long-strike with 6, taking the 13 stash.

(This page uses material from the Wikipedia article Kalah, which is released under the Commons Attribution-Share-Alike License 3.0.)