Hits creatures as +x weapon
In SLASH'EM and SlashTHEM, monsters can have the "hits creatures as a +x weapon" property, where x is an integer from 1 to 4 - monsters with the property will hit other monsters as weapon of the described enchantment. This is derived from Dungeons & Dragons alongside the "Need +x weapon to hit" property.
Note that these two properties are given to both new monsters and monsters from vanilla. It is possible to gain the "hits monsters as a +x weapon" property through polymorph, but not the "needs +x weapon to hit" property.
Description
The "hits creatures as +x weapon" property treats the monster's attacks as coming from a weapon of a certain enchantment, with the exact level of enchantment governed using a set of flags describing that enchantment (e.g., MR_HITASONE, MR_HITASTWO and so on). A monster with a MR_HITASFOUR flag, for instance, will hit other monsters as a +3 weapon.
In combat, this property is checked against a target's enchantment resistance if the attacker is not wielding a weapon. It is also intrinsic to monsters with enchantment resistance: a monster that is not given a specific "hits as" flag 'implicitly' hit as the same enchantment of weapon that they resist[1] - e.g., the Aleax has the MR_PLUSTWO flag but no MR_HITASFOO, so Aleaxes require a +2 weapon or better to hit and hit as +2 weapons themselves.
You can gain this property by polymorphing into an appropriate monster, though this does not confer the equivalent enchantment resistance.
Monks
The Monk is special in that while fighting bare-handed, they hit monsters as a +XL/4 weapon: a level 4-7 Monk hits as +1, level 8-11 Monks hit as +2, level 12-15 Monks hit as +3, and level 16+ Monks hit as +4.
Artifacts
Wielded artifacts that you attack with gain a +2 bonus to enchantment for purposes of checking whether you are able to hit a monster with "Need +x weapon to hit.[2] This also applies to other wielded artifacts that can be charged or enchanted; artifact boots and gloves are not counted.
Magicbane is always counted as a +4 weapon for this purpose, effectively ignoring all forms of enchantment resistance when you attack with it.[3]
Strategy
The ability to hit creatures as a +x weapon is of particular relevance to pet-keepers, especially pacifists who rely on their pets being able to reliably damage and kill monsters. Doppelganger characters can also use this to gain an edge against otherwise difficult-to-hit monsters in place of weapons they are unable to enchant to the required level, or even as a possible supplement to better-enchanted weapons.
