I developed the S.A.F.E acronym primarily to help beginning Martial Art & Self Defense students establish proper mindset sequence in preparation for defensive encounters.Very simple it goes as follows...
1. S- Scan...... Irregardless of your environment,you should always be on some low level of alert(see Jeff Cooper's Combat Mindset/Color Code System) just so you stay aware of your surroundings .You don't have to walk around constantly on guard or paranoid,but simply scan/quick search whatever location you happen to be at for possible threats or something out of the ordinary. Essentially "situational awareness".
2. A-Analyze......If you feel someone or something poses a potential risk,you need to identify & understand the nature of the threat by making a quick mental outline of the possible threat("threat assessment") and if someone or something is setting off your internal alarm system,but you can't perceive a threat or are unsure at all of the nature of the situation, assume a threat & move to step three.
3. F-Forethought...Here's where you mentally go over possible options.Trying to visualize & anticipate possible scenario's & how you should best respond. Try to foretell what is the most likely scenario to happen & prepare accordingly, but always expect the unexpected.
4. E-Employ....The action stage.This is when you actually apply the tactic best suited to deal with whatever threat materialized.It might be actual engagement/physical confrontation, escape/evasion or doing nothing at all.
* note....... The more experienced will go through the steps virtually simultaneously & there may be times when there is simply no time to analyze/assess a situation let alone develop a course of action, so that's where proper training is so important in developing reflexive & instinctive responses to surprise assaults.
The 3 D's consist of Detect-Defuse-Defend and share lot of commonality with the SAFE acronym albeit a shorter & simpler version and perhaps better one.It deals with violent threats specifically rather a whole broad analytical concept as SAFE does.Detect refers to seeing or detecting the threat as soon as possible in hopes to avoid altogether or have as much advanced warning as You can to have more time to process & react to the specific danger.Defuse means you want to try and "defuse"/deflect/de-escalate the situation rather than resorting to actual physical engagement.Defend means your avoidance and de-escalation attempts have failed and your forced to physically engage in a violent conflict to defend yourself/family/friends although escape should always be chosen if at any time during the engagement the opportunity presents itself and it can be done *SAFELY(trying to escape doesn't actually put you at greater risk than staying engaged) and/or is otherwise the best/safest course of action.
*Trying to escape doesn't put you or yours at greater risk than staying engaged or engaging.An example would be if a perp had a gun,it might be better to close and disarm than turn and run and get shot in the back(if he's intent on killing you).If he's already shooting and your not in contact distance then you probably want to move as quickly as possible to cover.Other times you might slowly back out of the situation facing the perp ready for a attack or bum rush. Turning and fighting vs getting stabbed in the back by a knife wielding attacker that you can't outrun etc although as long as your not in a trapped in very close quarters/contact distances,escape/running will likely be the first option.If you detect the attack early,then escape become even more likely.Sudden immediate & explosive movements to escape may take him off-guard and slow to react and give you a good headstart not matter how close of proximity you are at the start or even if path is blocked.If you have to actually perform a physical defensive movement against a knife,you should probably only have to do one since you should deflect the strike while moving toward escape.You might also "Burst"(see Krav Maga Bursting) or stun/run combing a counter simultaneously with your deflection.
Every situation is different and it might take more than one defensive move,you might not be able to escape and have to stay engaged and even finish the fight.It might be best to deflect with two hands in one scenario and a "burst"(simultaneous deflection/counterstrike)in another or a two handed parry and then counter & then burst etc.The variables are nearly endless so keep an open mind & play with different options.Primarily stick with "proven"(methods shown to have a high percentage of effectiveness and focus on the most likely to be encountered attacks although be prepared for the unexpected and be able to adapt and respond with unorthodox methods if needed as well as defend against unorthodox attacks even if you've never even seen what you or they use.Simpler gross motor skill movements are usually more reliable and effective due to being easier to perform under stress and the often time chaotic environment that is real-world self-defense conflict(especially unarmed defense),but a more dexterous or finesse move might be the best option and just what's needed to be effective.