I just realized that something my groups have been doing since I got into playing regularly is a complete homebrew. The reason I never realized this was probably because my groups are a variation of ~3 people that held together after another group fell through, where in that group, the GM (who ended up going AWOL) used this, and I think we simply kept using it without ever questioning if it was a real rule or not.

Maybe it is, and I just can't find it in the rule book(s) now that I'm looking for it. Anyway.

Critical Successes and Critical Failures.

When I started looking into Degrees of Success and how they apparently work differently in the various systems (DH/RT/DW vs. BC/OW), I noticed that there is nothing special about a roll of 1 and a roll of 100, except that 1 is always a success, and a 100 is always a failure.

No degrees or special effects, just a straight success and a straight failure (a single "degree" per the rules of BC/OW, obviously).

In my group(s) we've always considered a 1 a form of "Critical Success", often with very special repercussions, and I remember when I first came in contact with the core of my current groups, and I immediately rolled a 1 on Medicae, resulting in something like 7 DoS to boot, and the woman I was treating wasn't just fully patched up, but got +1 to a physical characteristic of her choice.

With a roll of 1, on an attack, every single shot hits. When trying to remember people with Intelligence, you not only remember their names, but their sick mother and that bad day they had on the job. That parry you made against the mook ended up cutting his head off with his own sword. While trying to pick a pocket with Sleight of Hand, you steal his tie, the coins in his shirt pocket, his watch, the notes you were going for, a ticket of passage to Scintilla and his even his pride.

Likewise, if you roll a 100, you've just managed to shoot yourself in the leg, short-circuited the ship cogitator array, or maybe even broken your weapon in a way that requires actual repair, beyond a mere jam. You've just fallen out of your hiding place straight into the enemy patrol, or set fire to your tent with that failed Trade (Cooking).

How do you handle rolls of 1 and 100? Is it anything special? Do you have any kind of system for "Critical" Successes and Failure? If so, anything formal, a straight-up rule, or guidelines? And if not, why not?

I think I will formalize this into a rule, but I'd like to hear some thoughts on the matter first.

I just rule it normally, per book. More than three degrees of failure or success is something critical, but not as much, as shooting yourself in the leg. 1% of outstanding failure is way too much. It's like having 1% chance, that every day piano will fall on your head.

Once I ruled i Warhammer Fantasy 2ed, that rolling 100 is auto fail without possibility of reroll, and since characters have usually more fate points than in Only War (minimum of 2 for humans for example, talent giving one additional luck point, magic charms etc). First session, one player rolled total of three 100's, but that is a different story.

PS: I like your sig.

I usually don't use critical success/fail tied to a specific number as it's a minor issue in a game that's less about pass/fail and more about degrees of same, and with re-rolls available.

Someone who has a high degree of skill, doing something simple, with a number of other advantages sufficient to give him a chance of success of 120% shouldn't have to worry about spontaneously combusting while backing his car out of the drive. While someone unskilled attempting something dangerous, using poor quality gear with a 15% chance of success deserves everything they get for rolling 5+ degrees of fail, and are unlikely to avoid it with a simple re-roll.

In my experience, critical fails happen without assistance. Example; PC fires Battlecannon, rolling 99%; rolls a 1 for Reliable, rolls a 0 for missile/grenade jam. Result; cannon destroyed, PC down to 1 wound, NPC VIP guide on crits and catapulted clean off the turret, falling 5m to the ground; killed on impact.

My group has always played 1-5 as rolling a "yes" (ignore armour on a called shot, pick hit location on a rgular shot, full heal) and 95-100 as rolling a "botch" (hit yourself, weapon jams, faceplant the obstacle you were jumping over, all at GMs discretion.)

I balanced this by applying it to NPCs as well. leading to some true terror of lethal killshots and unexpexted comedy like when the big bad my players had burst in on stabbed himself in his (unarmoured) arm with his toxin coated blade, rolled astoundingly for damage and died instantly choking and foaming without anyone so much as saying an angry word in his direction.