Some Alignment Weapons

Average Spear

Lawful and chaotic characters Save vs Magic or take 1d6 damage when picking this up. Even if they save, they are at disadvantage to use it but it otherwise works as a normal spear.

In the hands of a Neutral character, the spear come alive. It acts as a +2 weapon ... but with some complications. Critical hits and fumbles are ignored - every attack is an average hit or miss. Damage is always 5 (dice are not rolled, average of 3+2) plus STR and any other modifier. Healing (recovery or magic) always heals an average amount. Once per day the wielder can declare any die roll to be average BEFORE it is rolled.

These might suck. Just wanted to throw out a few ideas this morning.

Glaive of Law

Neutral characters simply can't touch the weapon, Chaotic characters that touch it Save vs Paralysis or are paralyzed for 1d6 Turns. 

Lawful characters carrying the glaive (pole-arm +1,+3 vs Chaotic foes) must always speak the truth, are unable to perform illegal or morally suspect acts, and may, 1/day, Command a group (total HD up to 1d4 per character level) and the command will be obeyed (assuming it isn't unlawful).

Chaos Mace

Lawful and Neutral characters see the chaos mace as filthy smear on reality. Lawful characters must Save vs wands or attack the wielder; if the wielder is an ally they can roll with Advantage (or +5 if you aren't into the Advantage thing). 

Damage is randomly determined each time the weapon hits (1d6)

1. 1d4 to the wielder
2. 0 damage
3. 1d4 to the target
4. 1d6 to the target
5. 1d8 to the target
6. 1d10 to the target

Against lawful targets the damage is +1d4. Once per week the wielder makes a Save vs Wands or they get a random mutation (which might be super awesome or crazy terrible).