The individual using the tit-for-tat strategy is

1. nice - it never cheats first

2. retaliatory - it responds to a partner that is cheating by cheating itself

3. forgiving - it only remembers one move back in time, and "forgives" earlier cheating.

• • Note that retaliation can lead to an unending "death spiral", which may be avoided by "tit for two tats", but this in turn may be vulnerable to cheaters.